code: func (b *Driver) Forward(val int) error {
  	b.pcmdMutex.Lock()
  	defer b.pcmdMutex.Unlock()
  
  	b.Pcmd.Flag = 1
  	b.Pcmd.Pitch = validatePitch(val)
  	return nil
  }
docs: // Forward tells the drone to go forward. Pass in an int from 0-100.