http://lucene.apache.org/lucene-parent/lucene-grouping: Lucene Grouping Module (The Apache Software Foundation) 
public class org.apache.lucene.search.grouping.TermGroupSelector extends org.apache.lucene.search.grouping.GroupSelector<org.apache.lucene.util.BytesRef>
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.apache.lucene.search.grouping.TermGroupSelector
  super_class: org.apache.lucene.search.grouping.GroupSelector
{
  private final java.lang.String field;
    descriptor: Ljava/lang/String;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private final org.apache.lucene.util.BytesRefHash values;
    descriptor: Lorg/apache/lucene/util/BytesRefHash;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  private final java.util.Map<java.lang.Integer, java.lang.Integer> ordsToGroupIds;
    descriptor: Ljava/util/Map;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/Map<Ljava/lang/Integer;Ljava/lang/Integer;>;

  private org.apache.lucene.index.SortedDocValues docValues;
    descriptor: Lorg/apache/lucene/index/SortedDocValues;
    flags: (0x0002) ACC_PRIVATE

  private int groupId;
    descriptor: I
    flags: (0x0002) ACC_PRIVATE

  private boolean secondPass;
    descriptor: Z
    flags: (0x0002) ACC_PRIVATE

  private boolean includeEmpty;
    descriptor: Z
    flags: (0x0002) ACC_PRIVATE

  private org.apache.lucene.util.BytesRef scratch;
    descriptor: Lorg/apache/lucene/util/BytesRef;
    flags: (0x0002) ACC_PRIVATE

  public void <init>(java.lang.String);
    descriptor: (Ljava/lang/String;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=2, args_size=2
        start local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
        start local 1 // java.lang.String field
         0: .line 50
            aload 0 /* this */
            invokespecial org.apache.lucene.search.grouping.GroupSelector.<init>:()V
         1: .line 37
            aload 0 /* this */
            new org.apache.lucene.util.BytesRefHash
            dup
            invokespecial org.apache.lucene.util.BytesRefHash.<init>:()V
            putfield org.apache.lucene.search.grouping.TermGroupSelector.values:Lorg/apache/lucene/util/BytesRefHash;
         2: .line 38
            aload 0 /* this */
            new java.util.HashMap
            dup
            invokespecial java.util.HashMap.<init>:()V
            putfield org.apache.lucene.search.grouping.TermGroupSelector.ordsToGroupIds:Ljava/util/Map;
         3: .line 85
            aload 0 /* this */
            new org.apache.lucene.util.BytesRef
            dup
            invokespecial org.apache.lucene.util.BytesRef.<init>:()V
            putfield org.apache.lucene.search.grouping.TermGroupSelector.scratch:Lorg/apache/lucene/util/BytesRef;
         4: .line 51
            aload 0 /* this */
            aload 1 /* field */
            putfield org.apache.lucene.search.grouping.TermGroupSelector.field:Ljava/lang/String;
         5: .line 52
            return
        end local 1 // java.lang.String field
        end local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    6     0   this  Lorg/apache/lucene/search/grouping/TermGroupSelector;
            0    6     1  field  Ljava/lang/String;
    MethodParameters:
       Name  Flags
      field  

  public void setNextReader(org.apache.lucene.index.LeafReaderContext);
    descriptor: (Lorg/apache/lucene/index/LeafReaderContext;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=5, args_size=2
        start local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
        start local 1 // org.apache.lucene.index.LeafReaderContext readerContext
         0: .line 56
            aload 0 /* this */
            aload 1 /* readerContext */
            invokevirtual org.apache.lucene.index.LeafReaderContext.reader:()Lorg/apache/lucene/index/LeafReader;
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.field:Ljava/lang/String;
            invokestatic org.apache.lucene.index.DocValues.getSorted:(Lorg/apache/lucene/index/LeafReader;Ljava/lang/String;)Lorg/apache/lucene/index/SortedDocValues;
            putfield org.apache.lucene.search.grouping.TermGroupSelector.docValues:Lorg/apache/lucene/index/SortedDocValues;
         1: .line 57
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.ordsToGroupIds:Ljava/util/Map;
            invokeinterface java.util.Map.clear:()V
         2: .line 58
            new org.apache.lucene.util.BytesRef
            dup
            invokespecial org.apache.lucene.util.BytesRef.<init>:()V
            astore 2 /* scratch */
        start local 2 // org.apache.lucene.util.BytesRef scratch
         3: .line 59
            iconst_0
            istore 3 /* i */
        start local 3 // int i
         4: goto 10
         5: .line 60
      StackMap locals: org.apache.lucene.util.BytesRef int
      StackMap stack:
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.values:Lorg/apache/lucene/util/BytesRefHash;
            iload 3 /* i */
            aload 2 /* scratch */
            invokevirtual org.apache.lucene.util.BytesRefHash.get:(ILorg/apache/lucene/util/BytesRef;)Lorg/apache/lucene/util/BytesRef;
            pop
         6: .line 61
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.docValues:Lorg/apache/lucene/index/SortedDocValues;
            aload 2 /* scratch */
            invokevirtual org.apache.lucene.index.SortedDocValues.lookupTerm:(Lorg/apache/lucene/util/BytesRef;)I
            istore 4 /* ord */
        start local 4 // int ord
         7: .line 62
            iload 4 /* ord */
            iflt 9
         8: .line 63
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.ordsToGroupIds:Ljava/util/Map;
            iload 4 /* ord */
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            iload 3 /* i */
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            invokeinterface java.util.Map.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
        end local 4 // int ord
         9: .line 59
      StackMap locals:
      StackMap stack:
            iinc 3 /* i */ 1
      StackMap locals:
      StackMap stack:
        10: iload 3 /* i */
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.values:Lorg/apache/lucene/util/BytesRefHash;
            invokevirtual org.apache.lucene.util.BytesRefHash.size:()I
            if_icmplt 5
        end local 3 // int i
        11: .line 65
            return
        end local 2 // org.apache.lucene.util.BytesRef scratch
        end local 1 // org.apache.lucene.index.LeafReaderContext readerContext
        end local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
      LocalVariableTable:
        Start  End  Slot           Name  Signature
            0   12     0           this  Lorg/apache/lucene/search/grouping/TermGroupSelector;
            0   12     1  readerContext  Lorg/apache/lucene/index/LeafReaderContext;
            3   12     2        scratch  Lorg/apache/lucene/util/BytesRef;
            4   11     3              i  I
            7    9     4            ord  I
    Exceptions:
      throws java.io.IOException
    MethodParameters:
               Name  Flags
      readerContext  

  public org.apache.lucene.search.grouping.GroupSelector$State advanceTo(int);
    descriptor: (I)Lorg/apache/lucene/search/grouping/GroupSelector$State;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=2
        start local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
        start local 1 // int doc
         0: .line 69
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.docValues:Lorg/apache/lucene/index/SortedDocValues;
            iload 1 /* doc */
            invokevirtual org.apache.lucene.index.SortedDocValues.advanceExact:(I)Z
            ifne 5
         1: .line 70
            aload 0 /* this */
            iconst_m1
            putfield org.apache.lucene.search.grouping.TermGroupSelector.groupId:I
         2: .line 71
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.includeEmpty:Z
            ifeq 3
            getstatic org.apache.lucene.search.grouping.GroupSelector$State.ACCEPT:Lorg/apache/lucene/search/grouping/GroupSelector$State;
            goto 4
      StackMap locals:
      StackMap stack:
         3: getstatic org.apache.lucene.search.grouping.GroupSelector$State.SKIP:Lorg/apache/lucene/search/grouping/GroupSelector$State;
      StackMap locals:
      StackMap stack: org.apache.lucene.search.grouping.GroupSelector$State
         4: areturn
         5: .line 73
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.docValues:Lorg/apache/lucene/index/SortedDocValues;
            invokevirtual org.apache.lucene.index.SortedDocValues.ordValue:()I
            istore 2 /* ord */
        start local 2 // int ord
         6: .line 74
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.ordsToGroupIds:Ljava/util/Map;
            iload 2 /* ord */
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            invokeinterface java.util.Map.containsKey:(Ljava/lang/Object;)Z
            ifeq 9
         7: .line 75
            aload 0 /* this */
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.ordsToGroupIds:Ljava/util/Map;
            iload 2 /* ord */
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            invokeinterface java.util.Map.get:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.lang.Integer
            invokevirtual java.lang.Integer.intValue:()I
            putfield org.apache.lucene.search.grouping.TermGroupSelector.groupId:I
         8: .line 76
            getstatic org.apache.lucene.search.grouping.GroupSelector$State.ACCEPT:Lorg/apache/lucene/search/grouping/GroupSelector$State;
            areturn
         9: .line 78
      StackMap locals: int
      StackMap stack:
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.secondPass:Z
            ifeq 11
        10: .line 79
            getstatic org.apache.lucene.search.grouping.GroupSelector$State.SKIP:Lorg/apache/lucene/search/grouping/GroupSelector$State;
            areturn
        11: .line 80
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.values:Lorg/apache/lucene/util/BytesRefHash;
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.docValues:Lorg/apache/lucene/index/SortedDocValues;
            invokevirtual org.apache.lucene.index.SortedDocValues.binaryValue:()Lorg/apache/lucene/util/BytesRef;
            invokevirtual org.apache.lucene.util.BytesRefHash.add:(Lorg/apache/lucene/util/BytesRef;)I
            putfield org.apache.lucene.search.grouping.TermGroupSelector.groupId:I
        12: .line 81
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.ordsToGroupIds:Ljava/util/Map;
            iload 2 /* ord */
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.groupId:I
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            invokeinterface java.util.Map.put:(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;
            pop
        13: .line 82
            getstatic org.apache.lucene.search.grouping.GroupSelector$State.ACCEPT:Lorg/apache/lucene/search/grouping/GroupSelector$State;
            areturn
        end local 2 // int ord
        end local 1 // int doc
        end local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0   14     0  this  Lorg/apache/lucene/search/grouping/TermGroupSelector;
            0   14     1   doc  I
            6   14     2   ord  I
    Exceptions:
      throws java.io.IOException
    Signature: (I)Lorg/apache/lucene/search/grouping/GroupSelector$State;
    MethodParameters:
      Name  Flags
      doc   

  public org.apache.lucene.util.BytesRef currentValue();
    descriptor: ()Lorg/apache/lucene/util/BytesRef;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
         0: .line 89
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.groupId:I
            iconst_m1
            if_icmpne 2
         1: .line 90
            aconst_null
            areturn
         2: .line 91
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.values:Lorg/apache/lucene/util/BytesRefHash;
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.groupId:I
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.scratch:Lorg/apache/lucene/util/BytesRef;
            invokevirtual org.apache.lucene.util.BytesRefHash.get:(ILorg/apache/lucene/util/BytesRef;)Lorg/apache/lucene/util/BytesRef;
            pop
         3: .line 92
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.scratch:Lorg/apache/lucene/util/BytesRef;
            areturn
        end local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    4     0  this  Lorg/apache/lucene/search/grouping/TermGroupSelector;

  public org.apache.lucene.util.BytesRef copyValue();
    descriptor: ()Lorg/apache/lucene/util/BytesRef;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
         0: .line 97
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.groupId:I
            iconst_m1
            if_icmpne 2
         1: .line 98
            aconst_null
            areturn
         2: .line 99
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            invokevirtual org.apache.lucene.search.grouping.TermGroupSelector.currentValue:()Lorg/apache/lucene/util/BytesRef;
            invokestatic org.apache.lucene.util.BytesRef.deepCopyOf:(Lorg/apache/lucene/util/BytesRef;)Lorg/apache/lucene/util/BytesRef;
            areturn
        end local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lorg/apache/lucene/search/grouping/TermGroupSelector;

  public void setGroups(java.util.Collection<org.apache.lucene.search.grouping.SearchGroup<org.apache.lucene.util.BytesRef>>);
    descriptor: (Ljava/util/Collection;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=4, args_size=2
        start local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
        start local 1 // java.util.Collection searchGroups
         0: .line 104
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.values:Lorg/apache/lucene/util/BytesRefHash;
            invokevirtual org.apache.lucene.util.BytesRefHash.clear:()V
         1: .line 105
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.values:Lorg/apache/lucene/util/BytesRefHash;
            invokevirtual org.apache.lucene.util.BytesRefHash.reinit:()V
         2: .line 106
            aload 1 /* searchGroups */
            invokeinterface java.util.Collection.iterator:()Ljava/util/Iterator;
            astore 3
            goto 7
      StackMap locals: org.apache.lucene.search.grouping.TermGroupSelector java.util.Collection top java.util.Iterator
      StackMap stack:
         3: aload 3
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            checkcast org.apache.lucene.search.grouping.SearchGroup
            astore 2 /* sg */
        start local 2 // org.apache.lucene.search.grouping.SearchGroup sg
         4: .line 107
            aload 2 /* sg */
            getfield org.apache.lucene.search.grouping.SearchGroup.groupValue:Ljava/lang/Object;
            ifnonnull 6
         5: .line 108
            aload 0 /* this */
            iconst_1
            putfield org.apache.lucene.search.grouping.TermGroupSelector.includeEmpty:Z
            goto 7
         6: .line 110
      StackMap locals: org.apache.lucene.search.grouping.TermGroupSelector java.util.Collection org.apache.lucene.search.grouping.SearchGroup java.util.Iterator
      StackMap stack:
            aload 0 /* this */
            getfield org.apache.lucene.search.grouping.TermGroupSelector.values:Lorg/apache/lucene/util/BytesRefHash;
            aload 2 /* sg */
            getfield org.apache.lucene.search.grouping.SearchGroup.groupValue:Ljava/lang/Object;
            checkcast org.apache.lucene.util.BytesRef
            invokevirtual org.apache.lucene.util.BytesRefHash.add:(Lorg/apache/lucene/util/BytesRef;)I
            pop
        end local 2 // org.apache.lucene.search.grouping.SearchGroup sg
         7: .line 106
      StackMap locals: org.apache.lucene.search.grouping.TermGroupSelector java.util.Collection top java.util.Iterator
      StackMap stack:
            aload 3
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 3
         8: .line 112
            aload 0 /* this */
            iconst_1
            putfield org.apache.lucene.search.grouping.TermGroupSelector.secondPass:Z
         9: .line 113
            return
        end local 1 // java.util.Collection searchGroups
        end local 0 // org.apache.lucene.search.grouping.TermGroupSelector this
      LocalVariableTable:
        Start  End  Slot          Name  Signature
            0   10     0          this  Lorg/apache/lucene/search/grouping/TermGroupSelector;
            0   10     1  searchGroups  Ljava/util/Collection<Lorg/apache/lucene/search/grouping/SearchGroup<Lorg/apache/lucene/util/BytesRef;>;>;
            4    7     2            sg  Lorg/apache/lucene/search/grouping/SearchGroup<Lorg/apache/lucene/util/BytesRef;>;
    Signature: (Ljava/util/Collection<Lorg/apache/lucene/search/grouping/SearchGroup<Lorg/apache/lucene/util/BytesRef;>;>;)V
    MethodParameters:
              Name  Flags
      searchGroups  

  public java.lang.Object currentValue();
    descriptor: ()Ljava/lang/Object;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokevirtual org.apache.lucene.search.grouping.TermGroupSelector.currentValue:()Lorg/apache/lucene/util/BytesRef;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public java.lang.Object copyValue();
    descriptor: ()Ljava/lang/Object;
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=1, locals=1, args_size=1
         0: .line 1
            aload 0
            invokevirtual org.apache.lucene.search.grouping.TermGroupSelector.copyValue:()Lorg/apache/lucene/util/BytesRef;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Lorg/apache/lucene/search/grouping/GroupSelector<Lorg/apache/lucene/util/BytesRef;>;
SourceFile: "TermGroupSelector.java"
InnerClasses:
  public final State = org.apache.lucene.search.grouping.GroupSelector$State of org.apache.lucene.search.grouping.GroupSelector