code: function() {
              var self        = this,
                  instruction = self.parseChangeLayoutArgs(arguments);
  
              return self.multimix({
                  changeLayout: instruction.command
              }, instruction.animate, instruction.callback);
          }
docs: Changes the layout of the container by adding, removing or updating a
  layout-specific class name. If `animation.animateResizetargets` is
  enabled, MixItUp will attempt to gracefully animate the width, height,
  and position of targets between layout states.
  
  @example
  
  .changeLayout(containerClassName [, animate] [, callback])
  
  @example <caption>Example 1: Adding a new class name to the container</caption>
  
  mixer.changeLayout('container-list')
  .then(function(state) {
  console.log(state.activeContainerClass === 'container-list'); // true
  });
  
  @example <caption>Example 2: Removing a previously added class name from the container</caption>
  
  mixer.changeLayout('')
  .then(function(state) {
  console.log(state.activeContainerClass === ''); // true
  });
  
  @public
  @instance
  @since       2.0.0
  @param       {string}    containerClassName
  A layout-specific class name to add to the container.
  @param       {boolean}   [animate=true]
  An optional boolean dictating whether the operation should animate, or occur syncronously with no animation. `true` by default.
  @param       {function}  [callback=null]
  An optional callback function to be invoked after the operation has completed.
  @return      {Promise.<mixitup.State>}
  A promise resolving with the current state object.