code: def lookup_field_label(self, context, field, default=None):
          
          # if this is a subfield, strip off everything but the last field name
          if field.find('.') >= 0:
              return self.lookup_field_label(context, field.split('.')[-1], default)
  
          label = None
  
          # is there a label specified for this field
          if field in self.field_config and 'label' in self.field_config[field]:
              label = self.field_config[field]['label']
  
          # if we were given a default, use that
          elif default:
              label = default
  
          # check our model
          else:
              for model_field in self.model._meta.fields:
                  if model_field.name == field:
                      return model_field.verbose_name.title()
  
          # otherwise, derive it from our field name
          if label is None:
              label = self.derive_field_label(field)
  
          return label
docs: Figures out what the field label should be for the passed in field name.
  
          Our heuristic is as follows:
              1) we check to see if our field_config has a label specified
              2) if not, then we derive a field value from the field name