C# collection mapper class

CollectionMapper.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace Utils.Lab.Mapping
{
    /// <summary>
    /// Mapper class converts a collection with the given predicate. 
    /// </summary>    
    public class CollectionMapper
    {
        private readonly bool _filterNull;

        public CollectionMapper(bool filterNull)
        {
            _filterNull = filterNull;
        }

        public CollectionMapper() : this(filterNull:false)
        {
        }

        public IEnumerable<TResult> ToCollection<TSource, TResult>(IEnumerable<TSource> collection, Func<TSource, TResult> predicate) where TSource : class
        {
            return ToCollectionInternal(collection, predicate);
        }
        
        public IList<TResult> ToCollection<TSource, TResult>(IList<TSource> collection, Func<TSource, TResult> predicate) where TSource : class
        {
            return ToCollectionInternal(collection, predicate).ToList();
        }

        public ICollection<TResult> ToCollection<TSource, TResult>(ICollection<TSource> collection, Func<TSource, TResult> predicate) where TSource : class
        {
            return ToCollectionInternal(collection, predicate).ToList();
        }

        private IEnumerable<TResult> ToCollectionInternal<TSource, TResult>(IEnumerable<TSource> collection, Func<TSource, TResult> predicate) where TSource : class
        {
            Validate(collection, predicate);

            if (_filterNull)
            {
                return collection.Where(item => item != null).Select(predicate);
            }

            return collection.Select(predicate);
        }

        private static void Validate(object entitiy, object predicate)
        {
            if (entitiy == null)
            {
                throw new ArgumentNullException("entitiy");
            }

            if (predicate == null)
            {
                throw new ArgumentNullException("predicate");
            }
        }
    }
}