code: def get_all_loopbacks(engine):
      
      data = []
      if 'fw_cluster' in engine.type:
          for cvi in engine.data.get('loopback_cluster_virtual_interface', []): 
              data.append(
                  LoopbackClusterInterface(cvi, engine))
      for node in engine.nodes:
          for lb in node.data.get('loopback_node_dedicated_interface', []):
              data.append(LoopbackInterface(lb, engine))
      return data
docs: Get all loopback interfaces for a given engine