code: function indentClassLeft( node, classes ) {
  		var indentClass = node.$.className.match( this.classNameRegex ),
  			isIndent = this.isIndent;
  
  		// If node has one of the indentClasses:
  		//	* If it holds the topmost indentClass, then
  		//	  no more classes have left.
  		//	* If it holds any other indentClass, it can use the next one
  		//	  or the previous one.
  		//	* Outdent is always possible. We can remove indentClass.
  		if ( indentClass )
  			return isIndent ? indentClass[ 1 ] != classes.slice( -1 ) : true;
  
  		// If node has no class which belongs to indentClasses,
  		// then it is at 0-level. It can be indented but not outdented.
  		else
  			return isIndent;
  	}
docs: Method that checks if current indentation level for an element reached the limit determined by config#indentClasses.