def xsd_error_log_string(xsd_error_log):
    """Return a human-readable string representation of the error log
    returned by lxml's XMLSchema validator.
    """
    ret = []
    for error in xsd_error_log:
        ret.append('ERROR ON LINE {}: {}'.format(error.line, error.message.
            encode('utf-8')))
    return '\n'.join(ret)
