Unable to delete custom message added in do_prepare method

Hi all,

I have added one custom error message in do_prepare method of partner table view and could see the error message populated for the expected scenario as I coded. Likewise I have to delete the custom message I added in code but I am not able to the method to achieve it.

Please help me out in this. PFB the code I used to add error message.

Thanks,

Karthik