public void TestContains()
        {
            var entities = this.database.CreateSimilarEntities(3, "Name 1");

            this.database.CreateSimilarEntities(3, "Name 2");
            this.database.CreateSimilarEntities(3, "Name 3");
            var builder    = new FilterExpressionBuilder <Entity, string>(nameof(Entity.Name), "e 1");
            var expression = builder.CreateContainsExpression();

            using (var context = this.database.Create())
            {
                var result = context.Entities
                             .Where(expression)
                             .ToList();
                Assert.Equal(entities, result, new PropertyComparer <Entity>());
            }
        }