code: def get_form_value(self, form_key, object_brain_uid, default=None):
          
          if form_key not in self.request.form:
              return default
  
          uid = object_brain_uid
          if not api.is_uid(uid):
              uid = api.get_uid(object_brain_uid)
  
          values = self.request.form.get(form_key)
          if isinstance(values, list):
              if len(values) == 0:
                  return default
              if len(values) > 1:
                  logger.warn("Multiple set of values for {}".format(form_key))
              values = values[0]
  
          return values.get(uid, default)
docs: Returns a value from the request's form for the given uid, if any