https://github.com/eclipse/eclipse-collections/eclipse-collections: Eclipse Collections is a collections framework for Java. It has JDK-compatible List, Set and Map implementations with a rich API and set of utility classes that work with any JDK compatible Collections, Arrays, Maps or Strings. The iteration protocol was inspired by the Smalltalk collection framework.
  • Craig P. Motlin
  • Donald Raab
  • Mohammad A. Rezaei
  • Hiroshi Ito
  • Nikhil J. Nanivadekar 
public final class org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure<T, K, V> implements org.eclipse.collections.api.block.procedure.Procedure<T>
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure
  super_class: java.lang.Object
{
  private static final long serialVersionUID;
    descriptor: J
    flags: (0x001a) ACC_PRIVATE, ACC_STATIC, ACC_FINAL
    ConstantValue: 1

  private final org.eclipse.collections.api.map.MutableMap<K, V> map;
    descriptor: Lorg/eclipse/collections/api/map/MutableMap;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lorg/eclipse/collections/api/map/MutableMap<TK;TV;>;

  private final org.eclipse.collections.api.block.function.Function<? super T, ? extends K> groupBy;
    descriptor: Lorg/eclipse/collections/api/block/function/Function;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lorg/eclipse/collections/api/block/function/Function<-TT;+TK;>;

  private final org.eclipse.collections.api.block.function.Function0<? extends V> zeroValueFactory;
    descriptor: Lorg/eclipse/collections/api/block/function/Function0;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lorg/eclipse/collections/api/block/function/Function0<+TV;>;

  private final org.eclipse.collections.api.block.procedure.Procedure2<? super V, ? super T> mutatingAggregator;
    descriptor: Lorg/eclipse/collections/api/block/procedure/Procedure2;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lorg/eclipse/collections/api/block/procedure/Procedure2<-TV;-TT;>;

  public void <init>(org.eclipse.collections.api.map.MutableMap<K, V>, org.eclipse.collections.api.block.function.Function<? super T, ? extends K>, org.eclipse.collections.api.block.function.Function0<? extends V>, org.eclipse.collections.api.block.procedure.Procedure2<? super V, ? super T>);
    descriptor: (Lorg/eclipse/collections/api/map/MutableMap;Lorg/eclipse/collections/api/block/function/Function;Lorg/eclipse/collections/api/block/function/Function0;Lorg/eclipse/collections/api/block/procedure/Procedure2;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=5, args_size=5
        start local 0 // org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure this
        start local 1 // org.eclipse.collections.api.map.MutableMap map
        start local 2 // org.eclipse.collections.api.block.function.Function groupBy
        start local 3 // org.eclipse.collections.api.block.function.Function0 zeroValueFactory
        start local 4 // org.eclipse.collections.api.block.procedure.Procedure2 mutatingAggregator
         0: .line 32
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 34
            aload 0 /* this */
            aload 1 /* map */
            putfield org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure.map:Lorg/eclipse/collections/api/map/MutableMap;
         2: .line 35
            aload 0 /* this */
            aload 2 /* groupBy */
            putfield org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure.groupBy:Lorg/eclipse/collections/api/block/function/Function;
         3: .line 36
            aload 0 /* this */
            aload 3 /* zeroValueFactory */
            putfield org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure.zeroValueFactory:Lorg/eclipse/collections/api/block/function/Function0;
         4: .line 37
            aload 0 /* this */
            aload 4 /* mutatingAggregator */
            putfield org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure.mutatingAggregator:Lorg/eclipse/collections/api/block/procedure/Procedure2;
         5: .line 38
            return
        end local 4 // org.eclipse.collections.api.block.procedure.Procedure2 mutatingAggregator
        end local 3 // org.eclipse.collections.api.block.function.Function0 zeroValueFactory
        end local 2 // org.eclipse.collections.api.block.function.Function groupBy
        end local 1 // org.eclipse.collections.api.map.MutableMap map
        end local 0 // org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure this
      LocalVariableTable:
        Start  End  Slot                Name  Signature
            0    6     0                this  Lorg/eclipse/collections/impl/block/procedure/MutatingAggregationProcedure<TT;TK;TV;>;
            0    6     1                 map  Lorg/eclipse/collections/api/map/MutableMap<TK;TV;>;
            0    6     2             groupBy  Lorg/eclipse/collections/api/block/function/Function<-TT;+TK;>;
            0    6     3    zeroValueFactory  Lorg/eclipse/collections/api/block/function/Function0<+TV;>;
            0    6     4  mutatingAggregator  Lorg/eclipse/collections/api/block/procedure/Procedure2<-TV;-TT;>;
    Signature: (Lorg/eclipse/collections/api/map/MutableMap<TK;TV;>;Lorg/eclipse/collections/api/block/function/Function<-TT;+TK;>;Lorg/eclipse/collections/api/block/function/Function0<+TV;>;Lorg/eclipse/collections/api/block/procedure/Procedure2<-TV;-TT;>;)V
    MethodParameters:
                    Name  Flags
      map                 
      groupBy             
      zeroValueFactory    
      mutatingAggregator  

  public void value();
    descriptor: (Ljava/lang/Object;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=4, args_size=2
        start local 0 // org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure this
        start local 1 // java.lang.Object each
         0: .line 43
            aload 0 /* this */
            getfield org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure.groupBy:Lorg/eclipse/collections/api/block/function/Function;
            aload 1 /* each */
            invokeinterface org.eclipse.collections.api.block.function.Function.valueOf:(Ljava/lang/Object;)Ljava/lang/Object;
            astore 2 /* key */
        start local 2 // java.lang.Object key
         1: .line 44
            aload 0 /* this */
            getfield org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure.map:Lorg/eclipse/collections/api/map/MutableMap;
            aload 2 /* key */
            aload 0 /* this */
            getfield org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure.zeroValueFactory:Lorg/eclipse/collections/api/block/function/Function0;
            invokeinterface org.eclipse.collections.api.map.MutableMap.getIfAbsentPut:(Ljava/lang/Object;Lorg/eclipse/collections/api/block/function/Function0;)Ljava/lang/Object;
            astore 3 /* value */
        start local 3 // java.lang.Object value
         2: .line 45
            aload 0 /* this */
            getfield org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure.mutatingAggregator:Lorg/eclipse/collections/api/block/procedure/Procedure2;
            aload 3 /* value */
            aload 1 /* each */
            invokeinterface org.eclipse.collections.api.block.procedure.Procedure2.value:(Ljava/lang/Object;Ljava/lang/Object;)V
         3: .line 46
            return
        end local 3 // java.lang.Object value
        end local 2 // java.lang.Object key
        end local 1 // java.lang.Object each
        end local 0 // org.eclipse.collections.impl.block.procedure.MutatingAggregationProcedure this
      LocalVariableTable:
        Start  End  Slot   Name  Signature
            0    4     0   this  Lorg/eclipse/collections/impl/block/procedure/MutatingAggregationProcedure<TT;TK;TV;>;
            0    4     1   each  TT;
            1    4     2    key  TK;
            2    4     3  value  TV;
    Signature: (TT;)V
    MethodParameters:
      Name  Flags
      each  
}
Signature: <T:Ljava/lang/Object;K:Ljava/lang/Object;V:Ljava/lang/Object;>Ljava/lang/Object;Lorg/eclipse/collections/api/block/procedure/Procedure<TT;>;
SourceFile: "MutatingAggregationProcedure.java"