/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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
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*/
/**
* Defines a {@link org.apache.isis.applib.clock.Clock} singleton
* that can be used to obtain the current time.
*
* <p>
* All of the built-in value types relating to time have
* {@link org.apache.isis.applib.adapters.ValueSemanticsProvider#getDefaultsProvider() defaults}
* that use the {@link org.apache.isis.applib.clock.Clock} singleton. For
* consistency, domain objects and services should also use the Clock.
*
* <p>
* Providing a clock is useful for testing, allowing the "current" time
* to be placed under programmatic control (by {@link org.apache.isis.applib.fixtures.FixtureClock#initialize() initializing}
* a {@link org.apache.isis.applib.fixtures.FixtureClock}. Otherwise though
* the {@link org.apache.isis.applib.clock.Clock} just uses the time from the
* current system.
*
* <p>
* Note: this design also means that other {@link org.apache.isis.applib.clock.Clock}
* implementations - such as a one that accesses the time from an NNTP time
* daemon - could also be used.
*/
package org.apache.isis.applib.clock;