code: def write_collection(self, collection_id, file_content, branch, author):
          
          gh_user = branch.split('_collection_')[0]
          msg = "Update Collection '%s' via OpenTree API" % collection_id
          return self.write_document(gh_user,
                                     collection_id,
                                     file_content,
                                     branch, author,
                                     commit_msg=msg)
docs: Given a collection_id, temporary filename of content, branch and auth_info
  
          Deprecated but needed until we merge api local-dep to master...