code: function (variableName) {
          var indexKey = this._postman_listIndexKey, // `key` for Variable
              variable = this.reference[variableName],
              i;
  
          if (variable && !variable.disabled) {
              return variable;
          }
  
          // traverse the members list in reverse direction in order to find the last enabled
          for (i = this.members.length - 1; i >= 0; i--) {
              variable = this.members[i];
              if (variable[indexKey] === variableName && !variable.disabled) {
                  // update the input variable reference if comparison is not disabled
                  this.reference[variableName] = variable;
                  break; // return updated reference variable
              }
          }
  
          return this.reference[variableName];
      }
docs: Fetches a variable and normalize its reference if disabled.
  This updates the disabled variable `reference` in VariableList with its
  last enabled duplicate(if found) in the `members` list.
  
  @private
  @param {String} variableName - The name of the variable to get
  @returns {Variable} - In case of duplicates, returns last enabled