nodejs GraphicsMagick (gm) passing stream to .composite()

Question

Using Expressjs with gm (GraphicsMagick) module.

I would like to use a stream as the input to .composite().

Is this possible, or is there any way of doing this?

I can composite using a path or a variable containing a path to an image, but I would like to pass in a stream instead (myStream).

Example:

var myStream = fs.createReadStream('topimage.png');

var resultStream = gm('/images/background.png')
                        .composite(myStream)
                        .gravity('Center')
                        .geometry('-1020+520')
                        .stream();