use Jstewmc\Model;

// define a concrete model with a single property, "foo"
class Foo extends Model
{
    protected static $properties = ['foo'];
}

// instantiate the new model
$model = new Foo();

// set foo's value
$model->foo = 'bar';

// test foo's value
isset($model->foo);  // returns true
echo $model->foo;    // returns "bar"
unset($model->foo);  // returns void
echo $model->foo;    // returns null
isset($model->foo);  // returns false

// ...continuing the example from above

$data = ['foo' => 'qux', 'baz' => 'bar'];

$model->hydrate($data);

echo $model->foo;    // returns "qux"
isset($model->baz);  // returns false