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// distributed with this work for additional information
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// 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
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using System.Collections.Generic;

namespace Org.Apache.REEF.Network.Group.Operators
{
    /// <summary>
    /// The class used to aggregate messages sent by ReduceSenders.
    /// </summary>
    /// <typeparam name="T">The message type.</typeparam>
    public interface IReduceFunction<T>
    {
        /// <summary>
        /// Reduce the IEnumerable of messages into one message.
        /// </summary>
        /// <param name="elements">The messages to reduce</param>
        /// <returns>The reduced message</returns>
        T Reduce(IEnumerable<T> elements);
    }
}