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 
class org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator extends org.eclipse.collections.impl.set.immutable.AbstractImmutableSet<T>.ImmutableSetIterator
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator
  super_class: org.eclipse.collections.impl.set.immutable.AbstractImmutableSet$ImmutableSetIterator
{
  final org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet this$0;
    descriptor: Lorg/eclipse/collections/impl/set/immutable/ImmutableDoubletonSet;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  private void <init>(org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet);
    descriptor: (Lorg/eclipse/collections/impl/set/immutable/ImmutableDoubletonSet;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator this
         0: .line 143
            aload 0 /* this */
            aload 1
            putfield org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator.this$0:Lorg/eclipse/collections/impl/set/immutable/ImmutableDoubletonSet;
            aload 0 /* this */
            aload 1
            invokespecial org.eclipse.collections.impl.set.immutable.AbstractImmutableSet$ImmutableSetIterator.<init>:(Lorg/eclipse/collections/impl/set/immutable/AbstractImmutableSet;)V
            return
        end local 0 // org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/eclipse/collections/impl/set/immutable/ImmutableDoubletonSet$DoubletonSetIterator;
    MethodParameters:
        Name  Flags
      this$0  final

  protected T getElement();
    descriptor: (I)Ljava/lang/Object;
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=5, locals=2, args_size=2
        start local 0 // org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator this
        start local 1 // int i
         0: .line 149
            iload 1 /* i */
            ifne 2
         1: .line 151
            aload 0 /* this */
            getfield org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator.this$0:Lorg/eclipse/collections/impl/set/immutable/ImmutableDoubletonSet;
            getfield org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet.element1:Ljava/lang/Object;
            areturn
         2: .line 153
      StackMap locals:
      StackMap stack:
            iload 1 /* i */
            iconst_1
            if_icmpne 4
         3: .line 155
            aload 0 /* this */
            getfield org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator.this$0:Lorg/eclipse/collections/impl/set/immutable/ImmutableDoubletonSet;
            getfield org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet.element2:Ljava/lang/Object;
            areturn
         4: .line 157
      StackMap locals:
      StackMap stack:
            new java.util.NoSuchElementException
            dup
            new java.lang.StringBuilder
            dup
            ldc "i="
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            iload 1 /* i */
            invokevirtual java.lang.StringBuilder.append:(I)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            invokespecial java.util.NoSuchElementException.<init>:(Ljava/lang/String;)V
            athrow
        end local 1 // int i
        end local 0 // org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    5     0  this  Lorg/eclipse/collections/impl/set/immutable/ImmutableDoubletonSet$DoubletonSetIterator;
            0    5     1     i  I
    Signature: (I)TT;
    MethodParameters:
      Name  Flags
      i     
}
Signature: Lorg/eclipse/collections/impl/set/immutable/AbstractImmutableSet<TT;>.ImmutableSetIterator;
SourceFile: "ImmutableDoubletonSet.java"
NestHost: org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet
InnerClasses:
  protected abstract ImmutableSetIterator = org.eclipse.collections.impl.set.immutable.AbstractImmutableSet$ImmutableSetIterator of org.eclipse.collections.impl.set.immutable.AbstractImmutableSet
  private DoubletonSetIterator = org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet$DoubletonSetIterator of org.eclipse.collections.impl.set.immutable.ImmutableDoubletonSet