@type t() :: %APM.Message.OpticalFlow{
  flow_comp_m_x: Float32,
  flow_comp_m_y: Float32,
  flow_rate_x: Float32,
  flow_rate_y: Float32,
  flow_x: MAVLink.Types.int16_t(),
  flow_y: MAVLink.Types.int16_t(),
  ground_distance: Float32,
  quality: MAVLink.Types.uint8_t(),
  sensor_id: MAVLink.Types.uint8_t(),
  time_usec: MAVLink.Types.uint64_t()
}