code: def removeClass(self, cn):
          '''Remove classes'''
          if cn:
              ks = self._classes
              if ks:
                  for cn in cn.split():
                      if cn in ks:
                          ks.remove(cn)
          return self removeClass(self, cn):
          '''Remove classes'''
          if cn:
              ks = self._classes
              if ks:
                  for cn in cn.split():
                      if cn in ks:
                          ks.remove(cn)
          return self
docs: Remove classes