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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 read(source, chatty=True, stop=None):
 """ Convert a NRML file into a validated Node object. Keeps the entire tree in memory. :param source: a file name or file object open for reading """

    vparser = ValidatingXmlParser(validators, stop)
    nrml = vparser.parse_file(source)
    if striptag(nrml.tag) != 'nrml':
        raise ValueError('%s: expected a node of kind nrml, got %s' %
                         (source, nrml.tag))
    # extract the XML namespace URL ('http://openquake.org/xmlns/nrml/0.5')
    xmlns = nrml.tag.split('}')[0][1:]
    if xmlns != NRML05 and chatty:
        # for the moment NRML04 is still supported, so we hide the warning
        logging.debug('%s is at an outdated version: %s', source, xmlns)
    nrml['xmlns'] = xmlns
    nrml['xmlns:gml'] = GML_NAMESPACE
    return nrml