https://www.graalvm.org/ 
class com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Error1 extends com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Base
  minor version: 0
  major version: 59
  flags: flags: (0x0020) ACC_SUPER
  this_class: com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Error1
  super_class: com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Base
{
  void <init>();
    descriptor: ()V
    flags: (0x0000) 
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Error1 this
         0: .line 120
            aload 0 /* this */
            invokespecial com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Base.<init>:()V
            return
        end local 0 // com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Error1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/dsl/test/InsertBeforeTest$InsertBefore1Error1;

  int f0(int);
    descriptor: (I)I
    flags: (0x0000) 
    Code:
      stack=1, locals=2, args_size=2
        start local 0 // com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Error1 this
        start local 1 // int a
         0: .line 125
            iload 1 /* a */
            ireturn
        end local 1 // int a
        end local 0 // com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Error1 this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lcom/oracle/truffle/api/dsl/test/InsertBeforeTest$InsertBefore1Error1;
            0    1     1     a  I
    RuntimeVisibleAnnotations: 
      com.oracle.truffle.api.dsl.test.ExpectError(value = {"Specializations can only be inserted before specializations in superclasses."})
      com.oracle.truffle.api.dsl.Specialization(insertBefore = "f0")
    RuntimeVisibleTypeAnnotations: 
      METHOD_RETURN
        com.oracle.truffle.api.dsl.test.ExpectError(value = {"Specializations can only be inserted before specializations in superclasses."})
    MethodParameters:
      Name  Flags
      a     
}
SourceFile: "InsertBeforeTest.java"
NestHost: com.oracle.truffle.api.dsl.test.InsertBeforeTest
InnerClasses:
  InsertBefore1Base = com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Base of com.oracle.truffle.api.dsl.test.InsertBeforeTest
  InsertBefore1Error1 = com.oracle.truffle.api.dsl.test.InsertBeforeTest$InsertBefore1Error1 of com.oracle.truffle.api.dsl.test.InsertBeforeTest
    RuntimeInvisibleAnnotations: 
      com.oracle.truffle.api.dsl.NodeChild(value = "a")