code: function _getRectangleImageCoordinates(startHandle, endHandle) {
    return {
      left: Math.min(startHandle.x, endHandle.x),
      top: Math.min(startHandle.y, endHandle.y),
      width: Math.abs(startHandle.x - endHandle.x),
      height: Math.abs(startHandle.y - endHandle.y),
    };
  }
docs: TODO: This is the same method (+ GetPixels) for the other ROIs
  TODO: The pixel filtering is the unique bit
  
  @param {*} startHandle
  @param {*} endHandle
  @returns {{ left: number, top: number, width: number, height: number}}