code: function (key) {
          var variable = this.values.oneNormalizedVariable(key),
              i,
              ii;
  
          // if a variable does not exist in local scope, we search all the layers and return the first occurrence.
          if (!(variable || !this._layers)) {
              for (i = 0, ii = this._layers.length; i < ii; i++) {
                  variable = this._layers[i].oneNormalizedVariable(key);
                  if (variable && !variable.disabled) { break; }
              }
          }
  
          return (variable && !variable.disabled) ? variable.valueOf() : undefined;
      }
docs: Fetches a variable from the current scope or from parent scopes if present.
  
  @param {String} key - The name of the variable to get.
  @returns {*} The value of the specified variable across scopes.