code: public function on($classObj)
      {
          $this->classObjOn = $classObj;
          $this->reflectionOn = new ReflectionClass($classObj);
          $this->isCalledAfterOn = true;
  
          return $this;
      }
docs: Getting the reflection.
  
  @param $classObj Object of the class the reflection to be created.
  
  @return $this