code: def build_vec(self):
          
          for item in all_calls:
              self.__dict__[item] = []
  
          for dev in self.devices:
              for item in all_calls:
                  if self.system.__dict__[dev].n == 0:
                      val = False
                  else:
                      val = self.system.__dict__[dev].calls.get(item, False)
                  self.__dict__[item].append(val)
docs: build call validity vector for each device