code: function createCopyContainers(acediff) {
    acediff.copyRightContainer = document.createElement('div');
    acediff.copyRightContainer.setAttribute('class', acediff.options.classes.copyRightContainer);
    acediff.copyLeftContainer = document.createElement('div');
    acediff.copyLeftContainer.setAttribute('class', acediff.options.classes.copyLeftContainer);
  
    document.getElementById(acediff.options.classes.gutterID).appendChild(acediff.copyRightContainer);
    document.getElementById(acediff.options.classes.gutterID).appendChild(acediff.copyLeftContainer);
  }
docs: creates two contains for positioning the copy left + copy right arrows