docs: def extract_value(self, data):
          """
          Extract the data from the request
          :param data: A mult-dict with either the post or get query
          """
          if self.name not in data and not self.allow_missing:
              raise exceptions.FieldNotFound('Field {} is missing from request'.format(self.name))
          
          if self.multiple_inputs:
              self.value = []
              for value in data.getlist(self.name):
                  if self.strip_value:
                      value = value.strip()
                  if value == '' and self.convert_empty_to_none:
                      value = None
  
                  self.value.append(value)
          else:
              self.value = data.get(self.name)
              if self.value is not None:
                  if self.strip_value:
                      self.value = self.value.strip()
                  if self.value == '' and self.convert_empty_to_none:
                      self.value = None
  
          # Convert the value to the correct data type
          self.convert_value()