code: def in_out_check(self):
          
          devices = available_devices()
          if not self.in_idx in devices:
              raise OSError("Input device is unavailable")
          in_check = devices[self.in_idx]
          if not self.out_idx in devices:
              raise OSError("Output device is unavailable")
          out_check = devices[self.out_idx]
          if((in_check['inputs'] == 0) and (out_check['outputs']==0)):
              raise StandardError('Invalid input and output devices')
          elif(in_check['inputs'] == 0):
              raise ValueError('Selected input device has no inputs')
          elif(out_check['outputs'] == 0):
              raise ValueError('Selected output device has no outputs')
          return True
docs: Checks the input and output to see if they are valid