docs: function envPlugin(dynamicConfig, options) {
      var self = this;
      var separator;
      var whitelist;
  
      if (options && typeof options === "object") {
          separator = options.separator;
          whitelist = options.whitelist;
      }
  
      this(dynamicConfig).after("loadConfigFile", function (result) {
          self.override.result = merge(result, process.env, separator, whitelist);
      });
  }