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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 update_custom_field_options(self, custom_field_key, new_options, keep_existing_options):
 """Updates the options of a multi-optioned custom field on this list."""

        custom_field_key = quote(custom_field_key, '')
        body = {
            "Options": new_options,
            "KeepExistingOptions": keep_existing_options}
        response = self._put(self.uri_for(
            "customfields/%s/options" % custom_field_key), json.dumps(body))