parse lazy data with evaluated variables mapping.
            Notice: variables_mapping should not contain any variable or function.

def to_value(self, variables_mapping=None):
        """ parse lazy data with evaluated variables mapping.
            Notice: variables_mapping should not contain any variable or function.
        """
        variables_mapping = variables_mapping or {}
        args = parse_lazy_data(self._args, variables_mapping)
        kwargs = parse_lazy_data(self._kwargs, variables_mapping)
        self.cache_key = self.__prepare_cache_key(args, kwargs)
        return self._func(*args, **kwargs)