text: /**
   * @author Stefan Schultz (Software Schultz)
   * 
   * Page object model to hold states.
   */
  let pageObjectModel = {
    unit: null, // null | 'mm' | 'in' | 'pt' | 'px' ==> mm==Millimeter, in==Inch/Zoll, pt==Point, px==Pixel
    pageWidth: null, // null | 1
    pageHeight: null, // null | 1
    // resolution: null, // null | 72 ==> 72 or 96 dpi/ppi
    pageOrientation: null, // null | 'p' | 'l' ==> p==portrait, l==landscape
    fileFormat: null, // null | 'pdf' | 'docx' | 'odt' | 'jpeg' | 'jpg' | 'png'
    fileName: null, // null | 'empty_page' ==> if nothing is set, then is default name set
    outputPath: null // null | './' ==> if nothing is set, then is default root path
  };
  
  const DEFAULT_UNIT = 'mm';
  const DEFAULT_PAGE_WIDTH = 1;
  const DEFAULT_PAGE_HEIGHT = 1;
  const DEFAULT_PAGE_ORIENTATION = 'p';
  const DEFAULT_PAGE_RESOLUTION = 72;
  const DEFAULT_FILE_NAME = 'empty_page';
  const DEFAULT_OUTPUT_PATH = './';
  
  module.exports = {
   pageObjectModel,
   DEFAULT_UNIT,
   DEFAULT_PAGE_WIDTH,
   DEFAULT_PAGE_HEIGHT,
   DEFAULT_PAGE_ORIENTATION,
   DEFAULT_PAGE_RESOLUTION,
   DEFAULT_FILE_NAME,
   DEFAULT_OUTPUT_PATH
  };