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. 
public interface com.google.common.cache.Weigher<K, V>
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: com.google.common.cache.Weigher
  super_class: java.lang.Object
{
  public abstract int weigh(K, );
    descriptor: (Ljava/lang/Object;Ljava/lang/Object;)I
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    Signature: (TK;TV;)I
    MethodParameters:
       Name  Flags
      key    
      value  
}
Signature: <K:Ljava/lang/Object;V:Ljava/lang/Object;>Ljava/lang/Object;
SourceFile: "Weigher.java"
    RuntimeVisibleAnnotations: 
      java.lang.FunctionalInterface()
    RuntimeInvisibleAnnotations: 
      com.google.common.annotations.GwtCompatible()