code: function(identifier, parent) {
          var parts = identifier.split('.');
          var i = 0;
          parent = parent || window;
          while (i < parts.length) {
              parent[parts[i]] = parent[parts[i]] || {};
              parent = parent[parts[i]];
              i++;
          }
          return parent;
      }
docs: Creates a namespcae hierarchy if not exists
  @param  {string} identifier - namespace identifier
  @return {object}