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.lazy.iterator.FlatCollectIterator<T, V> implements java.util.Iterator<V>
  minor version: 0
  major version: 59
  flags: flags: (0x0031) ACC_PUBLIC, ACC_FINAL, ACC_SUPER
  this_class: org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator
  super_class: java.lang.Object
{
  private final java.util.Iterator<T> iterator;
    descriptor: Ljava/util/Iterator;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Ljava/util/Iterator<TT;>;

  private final org.eclipse.collections.api.block.function.Function<? super T, ? extends java.lang.Iterable<V>> function;
    descriptor: Lorg/eclipse/collections/api/block/function/Function;
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL
    Signature: Lorg/eclipse/collections/api/block/function/Function<-TT;+Ljava/lang/Iterable<TV;>;>;

  private java.util.Iterator<V> innerIterator;
    descriptor: Ljava/util/Iterator;
    flags: (0x0002) ACC_PRIVATE
    Signature: Ljava/util/Iterator<TV;>;

  public void <init>(java.lang.Iterable<T>, org.eclipse.collections.api.block.function.Function<? super T, ? extends java.lang.Iterable<V>>);
    descriptor: (Ljava/lang/Iterable;Lorg/eclipse/collections/api/block/function/Function;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
        start local 1 // java.lang.Iterable iterable
        start local 2 // org.eclipse.collections.api.block.function.Function newFunction
         0: .line 29
            aload 0 /* this */
            aload 1 /* iterable */
            invokeinterface java.lang.Iterable.iterator:()Ljava/util/Iterator;
            aload 2 /* newFunction */
            invokespecial org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.<init>:(Ljava/util/Iterator;Lorg/eclipse/collections/api/block/function/Function;)V
         1: .line 30
            return
        end local 2 // org.eclipse.collections.api.block.function.Function newFunction
        end local 1 // java.lang.Iterable iterable
        end local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    2     0         this  Lorg/eclipse/collections/impl/lazy/iterator/FlatCollectIterator<TT;TV;>;
            0    2     1     iterable  Ljava/lang/Iterable<TT;>;
            0    2     2  newFunction  Lorg/eclipse/collections/api/block/function/Function<-TT;+Ljava/lang/Iterable<TV;>;>;
    Signature: (Ljava/lang/Iterable<TT;>;Lorg/eclipse/collections/api/block/function/Function<-TT;+Ljava/lang/Iterable<TV;>;>;)V
    MethodParameters:
             Name  Flags
      iterable     
      newFunction  

  public void <init>(java.util.Iterator<T>, org.eclipse.collections.api.block.function.Function<? super T, ? extends java.lang.Iterable<V>>);
    descriptor: (Ljava/util/Iterator;Lorg/eclipse/collections/api/block/function/Function;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
        start local 1 // java.util.Iterator newIterator
        start local 2 // org.eclipse.collections.api.block.function.Function newFunction
         0: .line 32
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 23
            aload 0 /* this */
            invokestatic org.eclipse.collections.impl.EmptyIterator.getInstance:()Lorg/eclipse/collections/impl/EmptyIterator;
            putfield org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.innerIterator:Ljava/util/Iterator;
         2: .line 36
            aload 0 /* this */
            aload 1 /* newIterator */
            putfield org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.iterator:Ljava/util/Iterator;
         3: .line 37
            aload 0 /* this */
            aload 2 /* newFunction */
            putfield org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.function:Lorg/eclipse/collections/api/block/function/Function;
         4: .line 38
            return
        end local 2 // org.eclipse.collections.api.block.function.Function newFunction
        end local 1 // java.util.Iterator newIterator
        end local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    5     0         this  Lorg/eclipse/collections/impl/lazy/iterator/FlatCollectIterator<TT;TV;>;
            0    5     1  newIterator  Ljava/util/Iterator<TT;>;
            0    5     2  newFunction  Lorg/eclipse/collections/api/block/function/Function<-TT;+Ljava/lang/Iterable<TV;>;>;
    Signature: (Ljava/util/Iterator<TT;>;Lorg/eclipse/collections/api/block/function/Function<-TT;+Ljava/lang/Iterable<TV;>;>;)V
    MethodParameters:
             Name  Flags
      newIterator  
      newFunction  

  public void remove();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
         0: .line 43
            new java.lang.UnsupportedOperationException
            dup
            ldc "Cannot remove from a flatCollect iterator"
            invokespecial java.lang.UnsupportedOperationException.<init>:(Ljava/lang/String;)V
            athrow
        end local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/eclipse/collections/impl/lazy/iterator/FlatCollectIterator<TT;TV;>;

  public boolean hasNext();
    descriptor: ()Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=3, locals=1, args_size=1
        start local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
         0: .line 51
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.innerIterator:Ljava/util/Iterator;
            invokeinterface java.util.Iterator.hasNext:()Z
            ifeq 2
         1: .line 53
            iconst_1
            ireturn
         2: .line 55
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.iterator:Ljava/util/Iterator;
            invokeinterface java.util.Iterator.hasNext:()Z
            ifne 4
         3: .line 57
            iconst_0
            ireturn
         4: .line 59
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.function:Lorg/eclipse/collections/api/block/function/Function;
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.iterator:Ljava/util/Iterator;
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            invokeinterface org.eclipse.collections.api.block.function.Function.valueOf:(Ljava/lang/Object;)Ljava/lang/Object;
            checkcast java.lang.Iterable
            invokeinterface java.lang.Iterable.iterator:()Ljava/util/Iterator;
            putfield org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.innerIterator:Ljava/util/Iterator;
         5: .line 49
            goto 0
        end local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    6     0  this  Lorg/eclipse/collections/impl/lazy/iterator/FlatCollectIterator<TT;TV;>;

  public V next();
    descriptor: ()Ljava/lang/Object;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
         0: .line 66
            aload 0 /* this */
            invokevirtual org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.hasNext:()Z
            ifne 2
         1: .line 68
            new java.util.NoSuchElementException
            dup
            invokespecial java.util.NoSuchElementException.<init>:()V
            athrow
         2: .line 70
      StackMap locals:
      StackMap stack:
            aload 0 /* this */
            getfield org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator.innerIterator:Ljava/util/Iterator;
            invokeinterface java.util.Iterator.next:()Ljava/lang/Object;
            areturn
        end local 0 // org.eclipse.collections.impl.lazy.iterator.FlatCollectIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lorg/eclipse/collections/impl/lazy/iterator/FlatCollectIterator<TT;TV;>;
    Signature: ()TV;
}
Signature: <T:Ljava/lang/Object;V:Ljava/lang/Object;>Ljava/lang/Object;Ljava/util/Iterator<TV;>;
SourceFile: "FlatCollectIterator.java"