content: /*****************************************************************
   *   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
   *
   *    https://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
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   *  specific language governing permissions and limitations
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   ****************************************************************/
  package org.apache.cayenne.ashwood.graph;
  
  import java.util.NoSuchElementException;
  
  class EmptyIterator<E, V> implements ArcIterator<E, V> {
  
  	@SuppressWarnings({ "rawtypes" })
  	private static final ArcIterator EMPTY_ITERATOR = new EmptyIterator<>();
  	
  	@SuppressWarnings("unchecked")
  	static <E, V> ArcIterator<E, V> instance() {
  		return EMPTY_ITERATOR;
  	}
  
  	@Override
  	public E getOrigin() {
  		return null;
  	}
  
  	@Override
  	public E getDestination() {
  		return null;
  	}
  
  	@Override
  	public boolean hasNext() {
  		return false;
  	}
  
  	@Override
  	public V next() {
  		throw new NoSuchElementException("Iterator contains no elements");
  	}
  
  	@Override
  	public void remove() {
  		throw new IllegalStateException("Iterator contains no elements");
  	}
  }