@staticmethod
def _read_file_block(file_handle, block_size=8192):
    """yield chunk_size blocks of file

        :param file_handle: handle to file
        :param chunk_size: block size of file to be read
        :return: block of file
        """
    while True:
        data = file_handle.read(block_size)
        if not data:
            break
        else:
            yield data
