indexOf(filter, [context])

Returns the first index of the element within the collection, or -1 if not found.

Note: A collection will not contain any duplicate items. All items within a collection are unique.

var shapes = Pablo(),
    shapeA =,
    shapeB = Pablo.rect(),
    shapeC = Pagitblo.ellipse();

shapes.push([shapeA, shapeB, shapeC]);

Painting is just another way of keeping a diary.
Pablo Picasso