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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 set_statements_pmid(self, pmid):
 """Set the evidence PMID of Statements that have been extracted. Parameters pmid : str or None The PMID to be used in the Evidence objects of the Statements that were extracted by the processor. """

        # Replace PMID value in JSON dict first
        for stmt in self.json_stmts:
            evs = stmt.get('evidence', [])
            for ev in evs:
                ev['pmid'] = pmid
        # Replace PMID value in extracted Statements next
        for stmt in self.statements:
            for ev in stmt.evidence:
                ev.pmid = pmid