code: function Canvas(width, height, gmsmith) {
    // Ignore width/height
    // DEV: Our canvas dimensions are dynamically defined by x/y of each image
    var canvas = gmsmith.gm(1, 1, 'transparent');
  
    // Override the -size options (won't work otherwise)
    canvas._in = ['-background', 'transparent'];
  
    // Save the canvas
    this.canvas = canvas;
  }
docs: Define our canvas constructor