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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def parse_config(filename, header):
 """ Parses the provided filename and returns ``SettingParser`` if the parsing was successful and header matches the header defined in the file. Returns ``SettingParser`` instance. * Raises a ``ParseError`` exception if header doesn't match or parsing fails. """


    parser = SettingParser(filename)
    if parser.header != header:
        header_value = parser.header or ''
        raise ParseError(u"Unexpected header '{0}', expecting '{1}'"
                         .format(common.from_utf8(header_value), header))

    return parser