code: def findSensor(self, sensors, sensor_name, device_type = None):
          
  
          if device_type == None:
              for sensor in sensors:
                  if sensor['name'] == sensor_name:
                      return sensor['id']
          else:
              for sensor in sensors:
                  if sensor['name'] == sensor_name and sensor['device_type'] == device_type:
                      return sensor['id']
  
          return None
docs: Find a sensor in the provided list of sensors
              
              @param sensors (list) - List of sensors to search in
              @param sensor_name (string) - Name of sensor to find
              @param device_type (string) - Device type of sensor to find, can be None
              
              @return (string) - sensor_id of sensor or None if not found