docs: function Parser(rfc822) {
  
      // ensure the input is a binary string
      this.rfc822 = (rfc822 || "").toString("binary");
  
      this._br = "";
      this._pos = 0;
  
      this.rawBody = "";
  
      this.tree = {
          childNodes: []
      };
      this._node = this.createNode(this.tree);
  }