docs: private void addCompilationErrorOnCustomMethodNode(InnerClassNode node, String methodName, Parameter[] parameters) {
          MethodNode existingMethodNode = node.getMethod(methodName, parameters);
          // if there is a user-defined methodNode, add compiler error msg and continue
          if (existingMethodNode != null && !isSynthetic(existingMethodNode))  {
              addError("\"" +methodName + "\" implementations are not supported on static inner classes as " +
                      "a synthetic version of \"" + methodName + "\" is added during compilation for the purpose " +
                      "of outer class delegation.",
                      existingMethodNode);
          }
      }