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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 process_xml(xml_str):
 """Return processor with Statements extracted from a Sparser XML. Parameters xml_str : str The XML string obtained by reading content with Sparser, using the 'xml' output mode. Returns ------- sp : SparserXMLProcessor A SparserXMLProcessor which has extracted Statements as its statements attribute. """

    try:
        tree = ET.XML(xml_str, parser=UTB())
    except ET.ParseError as e:
        logger.error('Could not parse XML string')
        logger.error(e)
        return None
    sp = _process_elementtree(tree)
    return sp