code: function PDU() {
      this.type = asn1ber.pduTypes.GetRequestPDU;
      this.reqid = 1;
      this.error = 0;
      this.errorIndex = 0;
      this.varbinds = [ new VarBind() ];
  }
docs: The `PDU` contains the SNMP request or response fields and a list of `VarBinds`.