Load data from raw_data or file_path

def _load_data(self):
        """
        Load data from raw_data or file_path
        """
        if self.raw_data is None and self.data_format is not FormatType.PYTHON:
            if self.file_path is None:
                raise ArgumentInvalid('One of "raw_data" or "file_path" should be set!')
            if not os.path.isfile(self.file_path) or not os.access(self.file_path, os.R_OK):
                raise ArgumentInvalid('"file_path" should be a valid path to an exist file with read permission!')
            with open(self.file_path) as f:
                self.raw_data = f.read()