@PUT @ApiIgnore // until documented
  @Path("{upgradeId}")
  @Produces("text/plain")
  public Response updateUpgradeItem(String body, @Context HttpHeaders headers,
      @Context UriInfo ui, @PathParam("upgradeId") Long id) {
    return handleRequest(headers, body, ui, Request.Type.PUT,
        createResourceInstance(id));
  }
Constructor.

@param clusterName the cluster name (not {@code null}).
ambari-server/src/main/java/org/apache/ambari/server/api/services/UpgradeService.java