code: function restoreGlobalDocument ( previousState ) {
  
          if ( previousState.documentElement.modified ) document.documentElement.style.overflowX = previousState.documentElement.styleOverflowX;
          if ( previousState.body.modified ) document.body.style.overflowX = previousState.body.styleOverflowX;
  
      }
docs: Restores the body and documentElement styles to their initial state, which is passed in as an argument. Works
  with the global document.
  
  Used only if iframe creation or access has failed for some reason.
  
  @param {Object} previousState  the initial state, as returned by prepareGlobalDocument()