public IQueryable<T> Search<T>(IQueryable<T> query, params Expression<Func<T, object>>[] memberSelectors)
            {
                if (PhraseGroups.Count() == 0)
                    return query;

                var phrasesParamExpression = Expression.Parameter(typeof(List<string>), "phrases");
                var phraseParamExpression = Expression.Parameter(typeof(string), "phrase");
                var entityParamExpression = Expression.Parameter(typeof(T), "entity");
                var memberSelectorParamExpression = Expression.Parameter(typeof(Expression<Func<T, object>>), "memberSelector");

                var condition = Expression.AndAlso(
                                    Expression.Equal(Expression.Invoke(memberSelectorParamExpression, entityParamExpression), Expression.Constant(null)),
                                     Expression.Call( Expression.Call(Expression.Invoke(memberSelectorParamExpression, entityParamExpression), typeof(object).GetMethod("ToString")) , typeof(string).GetMethod("Contains", new Type[] { typeof(string) }), phraseParamExpression)
                                 );


                var memberSelectorsExpression = Expression.Lambda<Func<Expression<Func<T, object>>, bool>>(condition, memberSelectorParamExpression);
                // this IEnumerable<TSource> source, Func<TSource, bool> predicate
                var anyMethod = typeof(Enumerable).GetMethods(BindingFlags.Static | BindingFlags.Public)
                                .First(m => m.Name == "Any" && m.GetParameters().Count() == 2);

                var phraseCondition = Expression.Lambda<Func<string, bool>>(Expression.Call(null, anyMethod.MakeGenericMethod(typeof(Expression<Func<T, object>>)), Expression.Constant(memberSelectors), memberSelectorsExpression), phraseParamExpression);

                var phrasesAnyExpr = Expression.Lambda<Func<List<string>, bool>>(Expression.Call(null, typeof(Enumerable).GetMethod("All").MakeGenericMethod(typeof(string)), phrasesParamExpression, phraseCondition), phrasesParamExpression);

                var whereCondition = Expression.Lambda<Func<T, bool>>(Expression.Call(null, anyMethod.MakeGenericMethod(typeof(List<string>)), Expression.Constant(PhraseGroups), phrasesAnyExpr), entityParamExpression);

                return query.Where(whereCondition);
            }