remove = function (parent)
    {
        //  Check to see if the parent is a canvas object
        var isCanvas = parent instanceof HTMLCanvasElement;

        pool.forEach(function (container)
        {
            if ((isCanvas && container.canvas === parent) || (!isCanvas && container.parent === parent))
            {
                container.parent = null;
                container.canvas.width = 1;
                container.canvas.height = 1;
            }
        });
    }
Looks up a canvas based on its parent, and if found puts it back in the pool, freeing it up for re-use.
The canvas has its width and height set to 1, and its parent attribute nulled.

@function Phaser.Display.Canvas.CanvasPool.remove
@since 3.0.0

@param {*} parent - The canvas or the parent of the canvas to free.