code: function createViewport () {
    const displayedArea = createDefaultDisplayedArea();
  
    return {
      scale: 1,
      translation: {
        x: 0,
        y: 0
      },
      voi: {
        windowWidth: undefined,
        windowCenter: undefined
      },
      invert: false,
      pixelReplication: false,
      rotation: 0,
      hflip: false,
      vflip: false,
      modalityLUT: undefined,
      voiLUT: undefined,
      colormap: undefined,
      labelmap: false,
      displayedArea
    };
  }
docs: Creates a new viewport object containing default values
  
  @returns {Viewport} viewport object
  @memberof Internal