code: public void detachVolume(String volumeId, String instanceId) {
          this.detachVolume(new DetachVolumeRequest().withVolumeId(volumeId).withInstanceId(instanceId));
      }
docs: Detaching the specified volume from a specified instance.
  
  You can detach the specified volume from a specified instance only
  when the instance is Running or Stopped ,
  otherwise,it's will get <code>409</code> errorCode.
  
  @param volumeId The id of the volume which has been attached to specified instance.
  @param instanceId The id of the instance which will be detached a volume.