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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 schematron_validate(mets_doc, schematron=AM_SCT_PATH):
 """Validate a METS file using a schematron schema. Return a boolean indicating validity and a report as an ``lxml.ElementTree`` instance. """

    if isinstance(schematron, six.string_types):
        schematron = get_schematron(schematron)
    is_valid = schematron.validate(mets_doc)
    report = schematron.validation_report
    return is_valid, report