How to specify grpcurl's (client's) port?

My sample grpc application uses host+port as a client id. However, grpcurl seems to make calls from a random port each time. I don't seem to find any flag in `grpcurl -help` that would allow to connect from a specific port. Am I missing something out? Thanks!

No file or test is named. Start with the grpcurl command-line flag definitions and its client-connection entry point, then determine whether a caller-selected source port is supported. Done should be a confirmed documented answer or a tested command-line option, depending on the project’s intended behavior.

Written by the indexing model from the issue text.