Returns the host name or IP string of the host where the session was started, if known. If
no host name or IP was specified when starting the session, this method returns {@code null}
@param key the session key to use to look up the target session.
@return the host name or ip address of the host where the session originated, if known. If unknown,
this method returns {@code null}.
Returns the host name or IP string of the host where the session was started, if known. If no host name or IP was specified when starting the session, this method returns {@code null}
@param key the session key to use to look up the target session. @return the host name or ip address of the host where the session originated, if known. If unknown, this method returns {@code null}.