def load_name_op(self, arg):
        """
        Partial realization

        Operation description:
            https://docs.python.org/3/library/dis.html#opcode-LOAD_NAME

        Operation realization:
            https://github.com/python/cpython/blob/3.7/Python/ceval.c#L2057
        """
        if arg in self.locals:
            val = self.locals[arg]
        elif arg in self.globals:
            val = self.globals[arg]
        elif arg in self.builtins:
            val = self.builtins[arg]
        else:
            raise NameError("name '%s' is not defined" % name)
        self.push(val)