code: def set_uppercase(self, uppercase):
          
          for row in self.rows:
              for key in row.keys:
                  if type(key) == VKey:
                      if uppercase:
                          key.value = key.value.upper()
                      else:
                          key.value = key.value.lower()
docs: Sets layout uppercase state.
  
          :param uppercase: True if uppercase, False otherwise.