class_docstr: Return a callable object that calls the given method on its operand.
  
  Unlike the builtin `operator.methodcaller`, instances of this class are
  serializable
code: def __new__(cls, method):
      if method in _method_cache:
          return _method_cache[method]
      self = object.__new__(cls)
      self.method = method
      _method_cache[method] = self
      return self
  
label_desc: Use image node_id 1 for calling the methodcaller obj's underlying member method code with example usage: obj.__new__(cls, method) and returns: self, _method_cache