code: private boolean isTrivialStackOps() {
  
          int invokeCount = 0;
          for (ActiveStackOp op : activeStackOps) {
              if (INVOKE_OPS.get(op.getOpcode())) {
                  invokeCount++;
              }
          }
  
          if (invokeCount == 1) {
              FQMethod method = activeStackOps.getLast().getMethod();
              if (method == null) {
                  return false;
              }
  
              if ("valueOf".equals(method.getMethodName()) && method.getClassName().startsWith("java/lang/")) {
                  return true;
              }
          }
  
          // do simple string appending?
  
          return false;
      }
docs: returns whether the set of operations that contributed to the current stack form, are trivial or not, specifically boxing a primitive value, or appending
  to strings or such.
  
  @return the operations that caused the current stack to exist are trivial