Generic Equality comparer that can be used of linq

Generic Equality comparer

using System;
using System.Collections.Generic;
 
namespace LightSwitchApplication
{
    /// <summary>
    /// Generic Equality comparer that can be used of linq
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class EqualityComparer<T> : IEqualityComparer<T>
    {
        private readonly Func<T, T, bool> _equalsFunction;
        private readonly Func<T, int> _getHashCodeFunction;
 
        public EqualityComparer(Func<T, T, bool> equalsFunction)
        {
            _equalsFunction = equalsFunction;
        }
 
        public EqualityComparer(Func<T, T, bool> equalsFunction,
                                Func<T, int> getHashCodeFunction)
            : this(equalsFunction)
        {
            _getHashCodeFunction = getHashCodeFunction;
        }
 
        public bool Equals(T a, T b)
        {
            return _equalsFunction(a, b);
        }
 
        public int GetHashCode(T obj)
        {
            if (_getHashCodeFunction == null)
                return obj.GetHashCode();
            return _getHashCodeFunction(obj);
        }
    }
}