code: function( filter, filterRoot, context ) {
  			// If this element's children were already filtered
  			// by current filter, don't filter them 2nd time.
  			// This situation may occur when filtering bottom-up
  			// (filterChildren() called manually in element's filter),
  			// or in unpredictable edge cases when filter
  			// is manipulating DOM structure.
  			if ( this.childrenFilteredBy == filter.id )
  				return;
  
  			context = this.getFilterContext( context );
  
  			// Filtering root if enforced.
  			if ( filterRoot && !this.parent )
  				filter.onRoot( context, this );
  
  			this.childrenFilteredBy = filter.id;
  
  			// Don't cache anything, children array may be modified by filter rule.
  			for ( var i = 0; i < this.children.length; i++ ) {
  				// Stay in place if filter returned false, what means
  				// that node has been removed.
  				if ( this.children[ i ].filter( filter, context ) === false )
  					i--;
  			}
  		}
docs: Filter this fragment's children with given filter.
  
  Element's children may only be filtered once by one
  instance of filter.
  
  @since 4.1
  @param {CKEDITOR.htmlParser.filter} filter
  @param {Boolean} [filterRoot] Whether to apply the "root" filter rule specified in the `filter`.