old_contents: !( function( factory ) {
    if ( typeof define === "function" && define.amd ) {
      define(factory );
    } else {
      factory( );
    }
  }(function( ){
  
    var imageView = null;
  
    var initImageView = function() {
      imageView = document.createElement('div');
      imageView.classList.add('imageView');
      imageView.innerHTML = '<span>&times;</span><div class="img"></div>';
      document.body.appendChild(imageView);
  
  
      imageView.querySelector('span').addEventListener('click', function() {
        imageView.style.opacity = 0;
        setTimeout(function(){
          imageView.style.zIndex = -1;
        }, 500)
      })
  
      return imageView;
    }
  
    document.addEventListener('click', function(e) {
      var target = e.target;
  
      if (target.getAttribute('data-role') === 'imageView') {
        if (!imageView) initImageView();
  
        imageView.querySelector('.img').style.backgroundImage = 'url(' + target.getAttribute('src') + ')';
        imageView.style.opacity = 1;
        imageView.style.zIndex = 200;
      }
    })
  
  
    return null;
  
  
  }));
  
new_contents: !( function( factory ) {
    if ( typeof define === "function" && define.amd ) {
      define(factory );
    } else {
      factory( );
    }
  }(function( ){
  
    var imageView = null;
  
    var initImageView = function() {
      imageView = document.createElement('div');
      imageView.classList.add('imageView');
      imageView.innerHTML = '<span>&times;</span><div class="img"></div>';
      document.body.appendChild(imageView);
  
  
      imageView.querySelector('span').addEventListener('click', function() {
        imageView.style.opacity = 0;
        setTimeout(function(){
          imageView.style.zIndex = -1;
        }, 500)
      })
  
      return imageView;
    }
  
    document.addEventListener('click', function(e) {
      var target = e.target;
  
      if (target.getAttribute('data-role') === 'imageView') {
        if (!imageView) initImageView();
  
        imageView.querySelector('.img').style.backgroundImage = 'url(' + target.getAttribute('src') + ')';
        imageView.style.opacity = 1;
        imageView.style.zIndex = 1001;
      }
    })
  
  
    return null;
  
  
  }));
  
subject: Update z-index.