def add_proof(self, certificate_metadata, merkle_proof):
certificate_json = self._get_certificate_to_issue(certificate_metadata)<EOL>certificate_json['<STR_LIT>'] = merkle_proof<EOL>with open(certificate_metadata.blockchain_cert_file_name, '<STR_LIT:w>') as out_file:<EOL><INDENT>out_file.write(json.dumps(certificate_json))<EOL><DEDENT>
:param certificate_metadata:
:param merkle_proof:
:return: