https://github.com/google/guava/guava: Guava is a suite of core and expanded libraries that include utility classes, google's collections, io classes, and much much more. 
final class com.google.common.collect.MapMakerInternalMap$CleanupMapTask implements java.lang.Runnable
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: com.google.common.collect.MapMakerInternalMap$CleanupMapTask
  super_class: java.lang.Object
{
  final java.lang.ref.WeakReference<com.google.common.collect.MapMakerInternalMap<?, ?, ?, ?>> mapReference;
    descriptor: Ljava/lang/ref/WeakReference;
    flags: (0x0010) ACC_FINAL
    Signature: Ljava/lang/ref/WeakReference<Lcom/google/common/collect/MapMakerInternalMap<****>;>;

  public void <init>(com.google.common.collect.MapMakerInternalMap<?, ?, ?, ?>);
    descriptor: (Lcom/google/common/collect/MapMakerInternalMap;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=4, locals=2, args_size=2
        start local 0 // com.google.common.collect.MapMakerInternalMap$CleanupMapTask this
        start local 1 // com.google.common.collect.MapMakerInternalMap map
         0: .line 2258
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
         1: .line 2259
            aload 0 /* this */
            new java.lang.ref.WeakReference
            dup
            aload 1 /* map */
            invokespecial java.lang.ref.WeakReference.<init>:(Ljava/lang/Object;)V
            putfield com.google.common.collect.MapMakerInternalMap$CleanupMapTask.mapReference:Ljava/lang/ref/WeakReference;
         2: .line 2260
            return
        end local 1 // com.google.common.collect.MapMakerInternalMap map
        end local 0 // com.google.common.collect.MapMakerInternalMap$CleanupMapTask this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    3     0  this  Lcom/google/common/collect/MapMakerInternalMap$CleanupMapTask;
            0    3     1   map  Lcom/google/common/collect/MapMakerInternalMap<****>;
    Signature: (Lcom/google/common/collect/MapMakerInternalMap<****>;)V
    MethodParameters:
      Name  Flags
      map   

  public void run();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=6, args_size=1
        start local 0 // com.google.common.collect.MapMakerInternalMap$CleanupMapTask this
         0: .line 2264
            aload 0 /* this */
            getfield com.google.common.collect.MapMakerInternalMap$CleanupMapTask.mapReference:Ljava/lang/ref/WeakReference;
            invokevirtual java.lang.ref.WeakReference.get:()Ljava/lang/Object;
            checkcast com.google.common.collect.MapMakerInternalMap
            astore 1 /* map */
        start local 1 // com.google.common.collect.MapMakerInternalMap map
         1: .line 2265
            aload 1 /* map */
            ifnonnull 3
         2: .line 2266
            new java.util.concurrent.CancellationException
            dup
            invokespecial java.util.concurrent.CancellationException.<init>:()V
            athrow
         3: .line 2269
      StackMap locals: com.google.common.collect.MapMakerInternalMap
      StackMap stack:
            aload 1 /* map */
            getfield com.google.common.collect.MapMakerInternalMap.segments:[Lcom/google/common/collect/MapMakerInternalMap$Segment;
            dup
            astore 5
            arraylength
            istore 4
            iconst_0
            istore 3
            goto 7
      StackMap locals: com.google.common.collect.MapMakerInternalMap$CleanupMapTask com.google.common.collect.MapMakerInternalMap top int int com.google.common.collect.MapMakerInternalMap$Segment[]
      StackMap stack:
         4: aload 5
            iload 3
            aaload
            astore 2 /* segment */
        start local 2 // com.google.common.collect.MapMakerInternalMap$Segment segment
         5: .line 2270
            aload 2 /* segment */
            invokevirtual com.google.common.collect.MapMakerInternalMap$Segment.runCleanup:()V
        end local 2 // com.google.common.collect.MapMakerInternalMap$Segment segment
         6: .line 2269
            iinc 3 1
      StackMap locals:
      StackMap stack:
         7: iload 3
            iload 4
            if_icmplt 4
         8: .line 2272
            return
        end local 1 // com.google.common.collect.MapMakerInternalMap map
        end local 0 // com.google.common.collect.MapMakerInternalMap$CleanupMapTask this
      LocalVariableTable:
        Start  End  Slot     Name  Signature
            0    9     0     this  Lcom/google/common/collect/MapMakerInternalMap$CleanupMapTask;
            1    9     1      map  Lcom/google/common/collect/MapMakerInternalMap<****>;
            5    6     2  segment  Lcom/google/common/collect/MapMakerInternalMap$Segment<****>;
}
SourceFile: "MapMakerInternalMap.java"
NestHost: com.google.common.collect.MapMakerInternalMap
InnerClasses:
  final CleanupMapTask = com.google.common.collect.MapMakerInternalMap$CleanupMapTask of com.google.common.collect.MapMakerInternalMap
  abstract Segment = com.google.common.collect.MapMakerInternalMap$Segment of com.google.common.collect.MapMakerInternalMap