Documentation for method close-stdin, assembled from the following types:
Closes the standard input stream of the external program. Programs that read from STDIN often only terminate when their input stream is closed. So if waiting for the promise from method start hangs (for a program opened for writing), it might be a forgotten
Proc::Async object must be created for writing (with
Proc::Async.new(:w, $path, @args)). Otherwise an X::Proc::Async::OpenForWriting exception will the thrown.
start must have been called before calling method close-stdin, otherwise an X::Proc::Async::MustBeStarted exception is thrown.