public void ShouldBeAString()
        {
            var value = new JsString("a");

            Assert.Equal(false, value.IsBoolean());
            Assert.Equal(false, value.IsArray());
            Assert.Equal(false, value.IsDate());
            Assert.Equal(false, value.IsNull());
            Assert.Equal(false, value.IsNumber());
            Assert.Equal(false, value.IsObject());
            Assert.Equal(true, value.IsPrimitive());
            Assert.Equal(false, value.IsRegExp());
            Assert.Equal(true, value.IsString());
            Assert.Equal("a", value.AsString());
            Assert.Equal(false, value.IsUndefined());
        }