docs: def save(self) -> None:
          """
          Saves all changed values to the database.
          """
          for name, field in self.fields.items():
              value = self.cleaned_data[name]
              if isinstance(value, UploadedFile):
                  # Delete old file
                  fname = self._s.get(name, as_type=File)
                  if fname:
                      try:
                          default_storage.delete(fname.name)
                      except OSError:  # pragma: no cover
                          logger.error('Deleting file %s failed.' % fname.name)
  
                  # Create new file
                  newname = default_storage.save(self.get_new_filename(value.name), value)
                  value._name = newname
                  self._s.set(name, value)
              elif isinstance(value, File):
                  # file is unchanged
                  continue
              elif isinstance(field, forms.FileField):
                  # file is deleted
                  fname = self._s.get(name, as_type=File)
                  if fname:
                      try:
                          default_storage.delete(fname.name)
                      except OSError:  # pragma: no cover
                          logger.error('Deleting file %s failed.' % fname.name)
                  del self._s[name]
              elif value is None:
                  del self._s[name]
              elif self._s.get(name, as_type=type(value)) != value:
                  self._s.set(name, value)