/*
 * Copyright (c) 2008-2021, Hazelcast, Inc. All Rights Reserved.
 *
 * 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
 *
 * 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 under the License.
 */

package com.hazelcast.internal.util;

import java.util.Iterator;

public class FlatCompositeIterator<E> extends AbstractCompositeIterator<E> {

    private final Iterator<Iterator<E>> iterators;

    public FlatCompositeIterator(Iterator<Iterator<E>> iterators) {
        this.iterators = iterators;
    }

    protected Iterator<E> nextIterator() {
        while (iterators.hasNext()) {
            Iterator<E> iterator = iterators.next();

            if (iterator.hasNext()) {
                return iterator;
            }
        }

        return null;
    }
}
