code: def verify(self, windowSize=None):
          if self.samplerate() is None:
              return "Multiple recording files with conflicting samplerates"
          msg = self._autoParams.verify()
          if msg:
              return msg
          if self.traceCount() == 0:
              return "Test is empty"
          if windowSize is not None:
              durations = self.expandFunction(self.duration)
              if durations[0] > windowSize or durations[-1] > windowSize:
                  return "Stimulus duration exceeds window duration"
          msg = self.verifyExpanded(self.samplerate())
          if msg:
              return msg
          if self.caldb is None or self.calv is None:
              return "Test reference voltage not set"
          if None in self.voltage_limits:
              return "Device voltage limits not set"
          return 0