code: def calculate_part_visibility(self, ports):
          # type: (APortMap) -> None
          
          # Calculate a lookup of Source Port connected_value to part_name
          source_port_lookup = {}
          for part_name, port_infos in SourcePortInfo.filter_parts(ports).items():
              for port_info in port_infos:
                  source_port_lookup[port_info.connected_value] = (
                      part_name, port_info.port)
          # Look through all the Sink Ports, and set both ends of the
          # connection to visible if they aren't specified
          for part_name, port_infos in SinkPortInfo.filter_parts(
                  ports).items():
              for port_info in port_infos:
                  if port_info.value != port_info.disconnected_value:
                      conn_part, port = source_port_lookup.get(
                          port_info.value, (None, None))
                      if conn_part and port == port_info.port:
                          if conn_part not in self.part_visibility:
                              self.part_visibility[conn_part] = True
                          if part_name not in self.part_visibility:
                              self.part_visibility[part_name] = True
docs: Calculate what is connected to what
  
          Args:
              ports: {part_name: [PortInfo]} from other ports