docs: def set_main_wire(self, wire=None):
  
          """
          Sets the specified wire as the link's main wire
          This is done automatically during the first wire() call
  
          Keyword Arguments:
  
              - wire (Wire): if None, use the first wire instance found
  
          Returns:
  
              - Wire: the new main wire instance
          """
  
          if not wire:
              for k in dir(self):
                  if isinstance(getattr(self, k), Wire):
                      wire = getattr(self, k)
                      break
          elif not isinstance(wire, Wire):
              raise ValueError("wire needs to be a Wire instance")
  
          if not isinstance(wire, Wire):
              wire = None
  
          self.main = wire
          return wire