code: def to_python(self, value):
          
          if value is None or value == '':
              return value
          if isinstance(value, base.Version):
              return value
          if self.coerce:
              return base.Version.coerce(value, partial=self.partial)
          else:
              return base.Version(value, partial=self.partial)
docs: Converts any value to a base.Version field.