code: def has_method(self, key: str) -> bool:
          
          return hasattr(self.__class__, key) and callable(getattr(self.__class__, key))
docs: Return if a method exists for the current instance.
  
          # Arguments
              key: The method name.
  
          # Returns:
              bool:
                  * True if the current instance has the provided method.
                  * False else.