http://fastutil.di.unimi.it/: fastutil extends the Java Collections Framework by providing type-specific maps, sets, lists and priority queues with a small memory footprint and fast access and insertion; provides also big (64-bit) arrays, sets and lists, and fast, practical I/O classes for binary and text files.
  • Sebastiano Vigna 
public abstract class it.unimi.dsi.fastutil.AbstractIndirectPriorityQueue<K> implements it.unimi.dsi.fastutil.IndirectPriorityQueue<K>
  minor version: 0
  major version: 59
  flags: flags: (0x0421) ACC_PUBLIC, ACC_SUPER, ACC_ABSTRACT
  this_class: it.unimi.dsi.fastutil.AbstractIndirectPriorityQueue
  super_class: java.lang.Object
{
  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // it.unimi.dsi.fastutil.AbstractIndirectPriorityQueue this
         0: .line 25
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // it.unimi.dsi.fastutil.AbstractIndirectPriorityQueue this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lit/unimi/dsi/fastutil/AbstractIndirectPriorityQueue<TK;>;
}
Signature: <K:Ljava/lang/Object;>Ljava/lang/Object;Lit/unimi/dsi/fastutil/IndirectPriorityQueue<TK;>;
SourceFile: "AbstractIndirectPriorityQueue.java"
    RuntimeVisibleAnnotations: 
      java.lang.Deprecated()