element/collage.js
function collage(width, height, forms) {
    return new Element(new CollageElement(forms, width, height)
        , width, height)
}
function collage(width, height, forms) {
    return new Element(new CollageElement(forms, width, height)
        , width, height)
}
function collage ( width , height , forms ) { return new Element ( new CollageElement ( forms , width , height ) , width , height ) }
Int -> Int -> [Form] -> Element
Int - > Int - > [ Form ] - > Element