code: function( priority ) {
  			var rules = this.rules,
  				len = rules.length,
  				i = len - 1;
  
  			// Search from the end, because usually rules will be added with default priority, so
  			// we will be able to stop loop quickly.
  			while ( i >= 0 && priority < rules[ i ].priority )
  				i--;
  
  			return i + 1;
  		}
docs: Finds an index at which rule with given priority should be inserted.
  
  @param {Number} priority
  @returns {Number} Index.