code: def check_siblings(self, individual_1_id, individual_2_id):
          
          
          self.logger.debug("Checking if {0} and {1} are siblings".format(
              individual_1_id, individual_2_id
          ))
          ind_1 = self.individuals[individual_1_id]
          ind_2 = self.individuals[individual_2_id]
          if ((ind_1.father != '0' and ind_1.father == ind_2.father) or 
              (ind_1.mother != '0' and ind_1.mother == ind_2.mother)):
              return True
          else:
              return False
docs: Check if two family members are siblings.
          
          Arguments: 
              individual_1_id (str): The id of an individual
              individual_2_id (str): The id of an individual
          
          Returns: 
              bool : True if the individuals are siblings
                     False if they are not siblings