// Copyright 2006, 2007, 2008, 2010 The Apache Software Foundation
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
is contributed to the
service, to allow contributed objects to replace other objects (typically, built in services).
contributionwill identify a contribution type and a non-null object that implements the type and may identify a mode. Only contributions where the mode is blank or the mode matches the provided mode are returned. Mode specific contributions quietly override non-specific contributions (where the mode is blank).