https://www.graalvm.org/ 
public interface com.oracle.truffle.tck.tests.ValueAssert$IsFunctionalInterfaceVarArgs
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: com.oracle.truffle.tck.tests.ValueAssert$IsFunctionalInterfaceVarArgs
  super_class: java.lang.Object
{
  public abstract java.lang.Object foobarbaz(java.lang.Object[]);
    descriptor: ([Ljava/lang/Object;)Ljava/lang/Object;
    flags: (0x0481) ACC_PUBLIC, ACC_VARARGS, ACC_ABSTRACT
    MethodParameters:
      Name  Flags
      args  
}
SourceFile: "ValueAssert.java"
NestHost: com.oracle.truffle.tck.tests.ValueAssert
InnerClasses:
  public abstract IsFunctionalInterfaceVarArgs = com.oracle.truffle.tck.tests.ValueAssert$IsFunctionalInterfaceVarArgs of com.oracle.truffle.tck.tests.ValueAssert
    RuntimeVisibleAnnotations: 
      java.lang.FunctionalInterface()