Ssh v2: examples of send_channel_request

Could anybody provide some examples of “send_channel_request” in ssh
V2? From manuals I only see the following without examples:

“If a block is given, it is registered as a callback for a pending
request, and the packet will be flagged so that the server knows a reply
is required. If no block is given, the server will send no response to
this request. Responses, where required, will cause the callback to be
invoked with the channel as the first argument, and either true or false
as the second, depending on whether the request succeeded or not.”

A few simple examples will be much clearer than only words! Thanks in