public ViewInstanceEntity getInstanceDefinition(String viewName, String version, String instanceName) {
    Map<String, ViewInstanceEntity> viewInstanceDefinitionMap =
        viewInstanceDefinitions.get(getDefinition(viewName, version));

    return viewInstanceDefinitionMap == null ? null : viewInstanceDefinitionMap.get(instanceName);
  }
Get the instance definition for the given view name and instance name.

@param viewName     the view name
@param version      the version
@param instanceName the instance name
@return the view instance definition for the given view and instance name
ambari-server/src/main/java/org/apache/ambari/server/view/ViewRegistry.java