code: function(block, element, modifier) {
          var seps = Toolkit.bemSeparators;
  
          if (element) {
              block += seps[0] + element;
          }
  
          if (modifier) {
              block += seps[1] + modifier;
          }
  
          return Toolkit.namespace + block;
      }
docs: Generate a BEM (block-element-modifier) valid CSS class name.
  
  @param {String} block
  @param {String} [element]
  @param {String} [modifier]
  @returns {String}