https://developers.google.com/protocol-buffers/protobuf-java/: Core Protocol Buffers library. Protocol Buffers are a way of encoding structured data in an efficient yet extensible format. 
public abstract class com.google.protobuf.AbstractMessageLite<MessageType extends com.google.protobuf.AbstractMessageLite<MessageType, BuilderType>, BuilderType extends com.google.protobuf.AbstractMessageLite$Builder<MessageType, BuilderType>> implements com.google.protobuf.MessageLite
  minor version: 0
  major version: 59
  flags: flags: (0x0421) ACC_PUBLIC, ACC_SUPER, ACC_ABSTRACT
  this_class: com.google.protobuf.AbstractMessageLite
  super_class: java.lang.Object
{
  protected int memoizedHashCode;
    descriptor: I
    flags: (0x0004) ACC_PROTECTED

  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.google.protobuf.AbstractMessageLite this
         0: .line 49
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 53
            aload 0 /* this */
            iconst_0
            putfield com.google.protobuf.AbstractMessageLite.memoizedHashCode:I
         2: .line 49
            return
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;

  public com.google.protobuf.ByteString toByteString();
    descriptor: ()Lcom/google/protobuf/ByteString;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=2, args_size=1
        start local 0 // com.google.protobuf.AbstractMessageLite this
         0: .line 58
            aload 0 /* this */
            invokevirtual com.google.protobuf.AbstractMessageLite.getSerializedSize:()I
            invokestatic com.google.protobuf.ByteString.newCodedBuilder:(I)Lcom/google/protobuf/ByteString$CodedBuilder;
            astore 1 /* out */
        start local 1 // com.google.protobuf.ByteString$CodedBuilder out
         1: .line 59
            aload 0 /* this */
            aload 1 /* out */
            invokevirtual com.google.protobuf.ByteString$CodedBuilder.getCodedOutput:()Lcom/google/protobuf/CodedOutputStream;
            invokevirtual com.google.protobuf.AbstractMessageLite.writeTo:(Lcom/google/protobuf/CodedOutputStream;)V
         2: .line 60
            aload 1 /* out */
            invokevirtual com.google.protobuf.ByteString$CodedBuilder.build:()Lcom/google/protobuf/ByteString;
         3: areturn
        end local 1 // com.google.protobuf.ByteString$CodedBuilder out
         4: .line 61
      StackMap locals:
      StackMap stack: java.io.IOException
            astore 1 /* e */
        start local 1 // java.io.IOException e
         5: .line 62
            new java.lang.RuntimeException
            dup
            aload 0 /* this */
            ldc "ByteString"
            invokevirtual com.google.protobuf.AbstractMessageLite.getSerializingExceptionMessage:(Ljava/lang/String;)Ljava/lang/String;
            aload 1 /* e */
            invokespecial java.lang.RuntimeException.<init>:(Ljava/lang/String;Ljava/lang/Throwable;)V
            athrow
        end local 1 // java.io.IOException e
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    6     0  this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;
            1    4     1   out  Lcom/google/protobuf/ByteString$CodedBuilder;
            5    6     1     e  Ljava/io/IOException;
      Exception table:
        from    to  target  type
           0     3       4  Class java.io.IOException

  public byte[] toByteArray();
    descriptor: ()[B
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=3, args_size=1
        start local 0 // com.google.protobuf.AbstractMessageLite this
         0: .line 69
            aload 0 /* this */
            invokevirtual com.google.protobuf.AbstractMessageLite.getSerializedSize:()I
            newarray 8
            astore 1 /* result */
        start local 1 // byte[] result
         1: .line 70
            aload 1 /* result */
            invokestatic com.google.protobuf.CodedOutputStream.newInstance:([B)Lcom/google/protobuf/CodedOutputStream;
            astore 2 /* output */
        start local 2 // com.google.protobuf.CodedOutputStream output
         2: .line 71
            aload 0 /* this */
            aload 2 /* output */
            invokevirtual com.google.protobuf.AbstractMessageLite.writeTo:(Lcom/google/protobuf/CodedOutputStream;)V
         3: .line 72
            aload 2 /* output */
            invokevirtual com.google.protobuf.CodedOutputStream.checkNoSpaceLeft:()V
         4: .line 73
            aload 1 /* result */
         5: areturn
        end local 2 // com.google.protobuf.CodedOutputStream output
        end local 1 // byte[] result
         6: .line 74
      StackMap locals:
      StackMap stack: java.io.IOException
            astore 1 /* e */
        start local 1 // java.io.IOException e
         7: .line 75
            new java.lang.RuntimeException
            dup
            aload 0 /* this */
            ldc "byte array"
            invokevirtual com.google.protobuf.AbstractMessageLite.getSerializingExceptionMessage:(Ljava/lang/String;)Ljava/lang/String;
            aload 1 /* e */
            invokespecial java.lang.RuntimeException.<init>:(Ljava/lang/String;Ljava/lang/Throwable;)V
            athrow
        end local 1 // java.io.IOException e
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    8     0    this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;
            1    6     1  result  [B
            2    6     2  output  Lcom/google/protobuf/CodedOutputStream;
            7    8     1       e  Ljava/io/IOException;
      Exception table:
        from    to  target  type
           0     5       6  Class java.io.IOException

  public void writeTo(java.io.OutputStream);
    descriptor: (Ljava/io/OutputStream;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=4, args_size=2
        start local 0 // com.google.protobuf.AbstractMessageLite this
        start local 1 // java.io.OutputStream output
         0: .line 81
            aload 0 /* this */
            invokevirtual com.google.protobuf.AbstractMessageLite.getSerializedSize:()I
            invokestatic com.google.protobuf.CodedOutputStream.computePreferredBufferSize:(I)I
            istore 2 /* bufferSize */
        start local 2 // int bufferSize
         1: .line 82
            aload 1 /* output */
            iload 2 /* bufferSize */
            invokestatic com.google.protobuf.CodedOutputStream.newInstance:(Ljava/io/OutputStream;I)Lcom/google/protobuf/CodedOutputStream;
            astore 3 /* codedOutput */
        start local 3 // com.google.protobuf.CodedOutputStream codedOutput
         2: .line 83
            aload 0 /* this */
            aload 3 /* codedOutput */
            invokevirtual com.google.protobuf.AbstractMessageLite.writeTo:(Lcom/google/protobuf/CodedOutputStream;)V
         3: .line 84
            aload 3 /* codedOutput */
            invokevirtual com.google.protobuf.CodedOutputStream.flush:()V
         4: .line 85
            return
        end local 3 // com.google.protobuf.CodedOutputStream codedOutput
        end local 2 // int bufferSize
        end local 1 // java.io.OutputStream output
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    5     0         this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;
            0    5     1       output  Ljava/io/OutputStream;
            1    5     2   bufferSize  I
            2    5     3  codedOutput  Lcom/google/protobuf/CodedOutputStream;
    Exceptions:
      throws java.io.IOException
    MethodParameters:
        Name  Flags
      output  final

  public void writeDelimitedTo(java.io.OutputStream);
    descriptor: (Ljava/io/OutputStream;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=5, args_size=2
        start local 0 // com.google.protobuf.AbstractMessageLite this
        start local 1 // java.io.OutputStream output
         0: .line 89
            aload 0 /* this */
            invokevirtual com.google.protobuf.AbstractMessageLite.getSerializedSize:()I
            istore 2 /* serialized */
        start local 2 // int serialized
         1: .line 92
            iload 2 /* serialized */
            invokestatic com.google.protobuf.CodedOutputStream.computeRawVarint32Size:(I)I
            iload 2 /* serialized */
            iadd
         2: .line 91
            invokestatic com.google.protobuf.CodedOutputStream.computePreferredBufferSize:(I)I
         3: .line 90
            istore 3 /* bufferSize */
        start local 3 // int bufferSize
         4: .line 93
            aload 1 /* output */
            iload 3 /* bufferSize */
            invokestatic com.google.protobuf.CodedOutputStream.newInstance:(Ljava/io/OutputStream;I)Lcom/google/protobuf/CodedOutputStream;
            astore 4 /* codedOutput */
        start local 4 // com.google.protobuf.CodedOutputStream codedOutput
         5: .line 94
            aload 4 /* codedOutput */
            iload 2 /* serialized */
            invokevirtual com.google.protobuf.CodedOutputStream.writeRawVarint32:(I)V
         6: .line 95
            aload 0 /* this */
            aload 4 /* codedOutput */
            invokevirtual com.google.protobuf.AbstractMessageLite.writeTo:(Lcom/google/protobuf/CodedOutputStream;)V
         7: .line 96
            aload 4 /* codedOutput */
            invokevirtual com.google.protobuf.CodedOutputStream.flush:()V
         8: .line 97
            return
        end local 4 // com.google.protobuf.CodedOutputStream codedOutput
        end local 3 // int bufferSize
        end local 2 // int serialized
        end local 1 // java.io.OutputStream output
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    9     0         this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;
            0    9     1       output  Ljava/io/OutputStream;
            1    9     2   serialized  I
            4    9     3   bufferSize  I
            5    9     4  codedOutput  Lcom/google/protobuf/CodedOutputStream;
    Exceptions:
      throws java.io.IOException
    MethodParameters:
        Name  Flags
      output  final

  int getMemoizedSerializedSize();
    descriptor: ()I
    flags: (0x0000) 
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // com.google.protobuf.AbstractMessageLite this
         0: .line 102
            new java.lang.UnsupportedOperationException
            dup
            invokespecial java.lang.UnsupportedOperationException.<init>:()V
            athrow
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;

  void setMemoizedSerializedSize(int);
    descriptor: (I)V
    flags: (0x0000) 
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.google.protobuf.AbstractMessageLite this
        start local 1 // int size
         0: .line 106
            new java.lang.UnsupportedOperationException
            dup
            invokespecial java.lang.UnsupportedOperationException.<init>:()V
            athrow
        end local 1 // int size
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;
            0    1     1  size  I
    MethodParameters:
      Name  Flags
      size  

  int getSerializedSize(com.google.protobuf.Schema);
    descriptor: (Lcom/google/protobuf/Schema;)I
    flags: (0x0000) 
    Code:
      stack=2, locals=3, args_size=2
        start local 0 // com.google.protobuf.AbstractMessageLite this
        start local 1 // com.google.protobuf.Schema schema
         0: .line 111
            aload 0 /* this */
            invokevirtual com.google.protobuf.AbstractMessageLite.getMemoizedSerializedSize:()I
            istore 2 /* memoizedSerializedSize */
        start local 2 // int memoizedSerializedSize
         1: .line 112
            iload 2 /* memoizedSerializedSize */
            iconst_m1
            if_icmpne 4
         2: .line 113
            aload 1 /* schema */
            aload 0 /* this */
            invokeinterface com.google.protobuf.Schema.getSerializedSize:(Ljava/lang/Object;)I
            istore 2 /* memoizedSerializedSize */
         3: .line 114
            aload 0 /* this */
            iload 2 /* memoizedSerializedSize */
            invokevirtual com.google.protobuf.AbstractMessageLite.setMemoizedSerializedSize:(I)V
         4: .line 116
      StackMap locals: int
      StackMap stack:
            iload 2 /* memoizedSerializedSize */
            ireturn
        end local 2 // int memoizedSerializedSize
        end local 1 // com.google.protobuf.Schema schema
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot                    Name  Signature
            0    5     0                    this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;
            0    5     1                  schema  Lcom/google/protobuf/Schema;
            1    5     2  memoizedSerializedSize  I
    MethodParameters:
        Name  Flags
      schema  

  com.google.protobuf.UninitializedMessageException newUninitializedMessageException();
    descriptor: ()Lcom/google/protobuf/UninitializedMessageException;
    flags: (0x0000) 
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.google.protobuf.AbstractMessageLite this
         0: .line 121
            new com.google.protobuf.UninitializedMessageException
            dup
            aload 0 /* this */
            invokespecial com.google.protobuf.UninitializedMessageException.<init>:(Lcom/google/protobuf/MessageLite;)V
            areturn
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;

  private java.lang.String getSerializingExceptionMessage(java.lang.String);
    descriptor: (Ljava/lang/String;)Ljava/lang/String;
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // com.google.protobuf.AbstractMessageLite this
        start local 1 // java.lang.String target
         0: .line 125
            new java.lang.StringBuilder
            dup
            ldc "Serializing "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
         1: .line 126
            aload 0 /* this */
            invokevirtual java.lang.Object.getClass:()Ljava/lang/Class;
            invokevirtual java.lang.Class.getName:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
         2: .line 127
            ldc " to a "
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
         3: .line 128
            aload 1 /* target */
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
         4: .line 129
            ldc " threw an IOException (should never happen)."
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
         5: .line 125
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            areturn
        end local 1 // java.lang.String target
        end local 0 // com.google.protobuf.AbstractMessageLite this
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    6     0    this  Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;
            0    6     1  target  Ljava/lang/String;
    MethodParameters:
        Name  Flags
      target  

  protected static void checkByteStringIsUtf8(com.google.protobuf.ByteString);
    descriptor: (Lcom/google/protobuf/ByteString;)V
    flags: (0x000c) ACC_PROTECTED, ACC_STATIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // com.google.protobuf.ByteString byteString
         0: .line 134
            aload 0 /* byteString */
            invokevirtual com.google.protobuf.ByteString.isValidUtf8:()Z
            ifne 2
         1: .line 135
            new java.lang.IllegalArgumentException
            dup
            ldc "Byte string is not UTF-8."
            invokespecial java.lang.IllegalArgumentException.<init>:(Ljava/lang/String;)V
            athrow
         2: .line 137
      StackMap locals:
      StackMap stack:
            return
        end local 0 // com.google.protobuf.ByteString byteString
      LocalVariableTable:
        Start  End  Slot        Name  Signature
            0    3     0  byteString  Lcom/google/protobuf/ByteString;
    Exceptions:
      throws java.lang.IllegalArgumentException
    MethodParameters:
            Name  Flags
      byteString  

  protected static <T> void addAll(java.lang.Iterable<T>, java.util.Collection<? super T>);
    descriptor: (Ljava/lang/Iterable;Ljava/util/Collection;)V
    flags: (0x000c) ACC_PROTECTED, ACC_STATIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // java.lang.Iterable values
        start local 1 // java.util.Collection list
         0: .line 142
            aload 0 /* values */
            aload 1 /* list */
            checkcast java.util.List
            invokestatic com.google.protobuf.AbstractMessageLite$Builder.addAll:(Ljava/lang/Iterable;Ljava/util/List;)V
         1: .line 143
            return
        end local 1 // java.util.Collection list
        end local 0 // java.lang.Iterable values
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    2     0  values  Ljava/lang/Iterable<TT;>;
            0    2     1    list  Ljava/util/Collection<-TT;>;
    Signature: <T:Ljava/lang/Object;>(Ljava/lang/Iterable<TT;>;Ljava/util/Collection<-TT;>;)V
    RuntimeVisibleAnnotations: 
      java.lang.Deprecated()
    MethodParameters:
        Name  Flags
      values  final
      list    final

  protected static <T> void addAll(java.lang.Iterable<T>, java.util.List<? super T>);
    descriptor: (Ljava/lang/Iterable;Ljava/util/List;)V
    flags: (0x000c) ACC_PROTECTED, ACC_STATIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // java.lang.Iterable values
        start local 1 // java.util.List list
         0: .line 146
            aload 0 /* values */
            aload 1 /* list */
            invokestatic com.google.protobuf.AbstractMessageLite$Builder.addAll:(Ljava/lang/Iterable;Ljava/util/List;)V
         1: .line 147
            return
        end local 1 // java.util.List list
        end local 0 // java.lang.Iterable values
      LocalVariableTable:
        Start  End  Slot    Name  Signature
            0    2     0  values  Ljava/lang/Iterable<TT;>;
            0    2     1    list  Ljava/util/List<-TT;>;
    Signature: <T:Ljava/lang/Object;>(Ljava/lang/Iterable<TT;>;Ljava/util/List<-TT;>;)V
    MethodParameters:
        Name  Flags
      values  final
      list    final
}
Signature: <MessageType:Lcom/google/protobuf/AbstractMessageLite<TMessageType;TBuilderType;>;BuilderType:Lcom/google/protobuf/AbstractMessageLite$Builder<TMessageType;TBuilderType;>;>Ljava/lang/Object;Lcom/google/protobuf/MessageLite;
SourceFile: "AbstractMessageLite.java"
NestMembers:
  com.google.protobuf.AbstractMessageLite$Builder  com.google.protobuf.AbstractMessageLite$Builder$LimitedInputStream  com.google.protobuf.AbstractMessageLite$InternalOneOfEnum
InnerClasses:
  public abstract Builder = com.google.protobuf.AbstractMessageLite$Builder of com.google.protobuf.AbstractMessageLite
  protected abstract InternalOneOfEnum = com.google.protobuf.AbstractMessageLite$InternalOneOfEnum of com.google.protobuf.AbstractMessageLite
  final CodedBuilder = com.google.protobuf.ByteString$CodedBuilder of com.google.protobuf.ByteString