@GET @ApiIgnore // until documented
  @Path("{stageId}")
  @Produces("text/plain")
  public Response getStage(String body, @Context HttpHeaders headers, @Context UriInfo ui,
                           @PathParam("stageId") String stageId) {

    return handleRequest(headers, body, ui, Request.Type.GET,
        createStageResource(m_clusterName, m_requestId, stageId));
  }
Handles URL: /clusters/{clusterID}/requests/{requestID}/stages/{stageID} or
/requests/{requestId}/stages/{stageID}
Get a specific stage.

@param headers  http headers
@param ui       uri info
@param stageId  stage id

@return stage resource representation
ambari-server/src/main/java/org/apache/ambari/server/api/services/StageService.java