<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_label_fields(self):
 """ Get the present label fields in the object """

        present_label_fields = []
        for field in ann_label_fields:
            if getattr(self, field) is not None:
                present_label_fields.append(field)

        return present_label_fields