Optional attributes in Map Policy

Case ID: TS001086991

If an attribute is not present in the input, the Map Policy logs an error message like below.

[apiconnect][error] mpgw(webapi): tid(11724809)[request][aaa.aaa.aaa.aaa] gtid(11724809): Map: API=test-api, policy=Map1: input : set action aaa.bbb.ccc: ddd is undefined and has no default configured.

If there are lots of such non-present attributes and there are lots of API calls, the DataPower log files are quickly rotated and log messages are lost very quickly.

The RFE ( http://www.ibm.com/developerworks/rfe/execute?use_case=viewRfe&CR_ID=112659) addressed the same issue but it requested a way to filter out the error messages. However, filtering out messages by error id requires configuration change in the Log Target and it will introduce extra maintenance works.
(Ref: https://developer.ibm.com/answers/questions/462486/how-do-i-reduce-or-remove-the-apic-map-policy-inpu.html#‌answer-462498)

In this RFE, I would like to request to have some Map Policy option so that the Map Policy doesn't output the error messages for the missing attributes.
I think this is a reasonable option because there would often be a situation where no output attribute is wanted to be generated instead of a default value if the corresponding input attribute does not exist. They are optional attributes.