private static BacNetObject createTrendLog() {
        return b("Trend Log",
            p("Object_Identifier", "BACnetObjectIdentifier", c(R)),
            p("Object_Name", "CharacterString", c(R)),
            p("Object_Type", "BACnetObjectType", c(R)),
            p("Description", "CharacterString", c(O)),
            p("Enable", "BOOLEAN", c(W)),
            p("Start_Time", "BACnetDateTime", c(O, 1, 2)),
            p("Stop_Time", "BACnetDateTime", c(O, 1, 2)),
            p("Log_DeviceObjectProperty", "BACnetDeviceObjectPropertyReference", c(O, 8)),
            p("Log_Interval", "Unsigned", c(O, 1, 3)),
            p("COV_Resubscription_Interval", "Unsigned", c(O)),
            p("Client_COV_Increment", "BACnetClientCOV", c(O)),
            p("Stop_When_Full", "BOOLEAN", c(R)),
            p("Buffer_Size", "Unsigned32", c(R)),
            p("Log_Buffer", "BACnetLIST of BACnetLogRecord", c(R)),
            p("Record_Count", "Unsigned32", c(W)),
            p("Total_Record_Count", "Unsigned32", c(R)),
            p("Logging_Type", "BACnetLoggingType", c(R)),
            p("Align_Intervals", "BOOLEAN", c(O, 5)),
            p("Interval_Offset", "Unsigned", c(O, 5)),
            p("Trigger", "BOOLEAN", c(O)),
            p("Status_Flags", "BACnetStatusFlags", c(R)),
            p("Reliability", "BACnetReliability", c(O)),
            p("Notification_Threshold", "Unsigned32", c(O, 4, 7)),
            p("Records_Since_Notification", "Unsigned32", c(O, 4, 7)),
            p("Last_Notify_Record", "Unsigned32", c(O, 4, 7)),
            p("Event_State", "BACnetEventState", c(R)),
            p("Notification_Class", "Unsigned", c(O, 4, 7)),
            p("Event_Enable", "BACnetEventTransitionBits", c(O, 4, 7)),
            p("Acked_Transitions", "BACnetEventTransitionBits", c(O, 4, 7)),
            p("Notify_Type", "BACnetNotifyType", c(O, 4, 7)),
            p("Event_Time_Stamps", "BACnetARRAY[3] of BACnetTimeStamp", c(O, 4, 7)),
            p("Event_Message_Texts", "BACnetARRAY[3] of CharacterString", c(O, 7)),
            p("Event_Message_Texts_Config", "BACnetARRAY[3] of CharacterString", c(O, 7)),
            p("Event_Detection_Enable", "BOOLEAN", c(O, 4, 7)),
            p("Event_Algorithm_Inhibit_Ref", "BACnetObjectPropertyReference", c(O, 7)),
            p("Event_Algorithm_Inhibit", "BOOLEAN", c(O, 7, 9)),
            p("Reliability_Evaluation_Inhibit", "BOOLEAN", c(O, 10)),
            p("Property_List", "BACnetARRAY[N] of BACnetPropertyIdentifier", c(R)),
            p("Tags", "BACnetARRAY[N] of BACnetNameValue", c(O)),
            p("Profile_Location", "CharacterString", c(O)),
            p("Profile_Name", "CharacterString", c(O))
        );
    }
a map which maps property to type variants
protocols/bacnetip/src/test/java/org/apache/plc4x/protocol/bacnetip/BACnetObjectsDefinitions.java