https://www.graalvm.org/ 
public interface com.oracle.truffle.api.ReplaceObserver
  minor version: 0
  major version: 59
  flags: flags: (0x0601) ACC_PUBLIC, ACC_INTERFACE, ACC_ABSTRACT
  this_class: com.oracle.truffle.api.ReplaceObserver
  super_class: java.lang.Object
{
  public abstract boolean nodeReplaced(com.oracle.truffle.api.nodes.Node, com.oracle.truffle.api.nodes.Node, java.lang.CharSequence);
    descriptor: (Lcom/oracle/truffle/api/nodes/Node;Lcom/oracle/truffle/api/nodes/Node;Ljava/lang/CharSequence;)Z
    flags: (0x0401) ACC_PUBLIC, ACC_ABSTRACT
    MethodParameters:
         Name  Flags
      oldNode  
      newNode  
      reason   
}
SourceFile: "ReplaceObserver.java"