code: def add_author(self, author, file_as=None, role=None, uid='creator'):
          "Add author for this document"
  
          self.add_metadata('DC', 'creator', author, {'id': uid})
  
          if file_as:
              self.add_metadata(None, 'meta', file_as, {'refines': '#' + uid,
                                                        'property': 'file-as',
                                                        'scheme': 'marc:relators'})
          if role:
              self.add_metadata(None, 'meta', role, {'refines': '#' + uid,
                                                     'property': 'role',
                                                     'scheme': 'marc:relators'}f add_author(self, author, file_as=None, role=None, uid='creator'):
          "Add author for this document"
  
          self.add_metadata('DC', 'creator', author, {'id': uid})
  
          if file_as:
              self.add_metadata(None, 'meta', file_as, {'refines': '#' + uid,
                                                        'property': 'file-as',
                                                        'scheme': 'marc:relators'})
          if role:
              self.add_metadata(None, 'meta', role, {'refines': '#' + uid,
                                                     'property': 'role',
                                                     'scheme': 'marc:relators'})
docs: Add author for this document