def register_doi(self, submission_id, request_xml):
endpoint = self.get_endpoint('<STR_LIT>')<EOL>files = {<EOL>'<STR_LIT>': ('<STR_LIT>' % submission_id, request_xml)<EOL>}<EOL>params = {<EOL>'<STR_LIT>': '<STR_LIT>',<EOL>'<STR_LIT>': self.api_user,<EOL>'<STR_LIT>': self.api_key<EOL>}<EOL>result = self.do_http_request(<EOL>'<STR_LIT>',<EOL>endpoint,<EOL>data=params,<EOL>files=files,<EOL>timeout=<NUM_LIT:10>,<EOL>custom_header=str(self.etiquette)<EOL>)<EOL>return result<EOL>
This method registry a new DOI number in Crossref or update some DOI
metadata.

submission_id: Will be used as the submission file name. The file name
could be used in future requests to retrieve the submission status.

request_xml: The XML with the document metadata. It must be under
compliance with the Crossref Submission Schema.