def __init__(self, beaver_config, logger=None):
super(BeaverSubprocess, self).__init__(logger=logger)<EOL>self._log_template = '<STR_LIT>'<EOL>self._beaver_config = beaver_config<EOL>self._command = '<STR_LIT>'<EOL>self._subprocess = None<EOL>self._logger = logger<EOL>
Child classes should build a subprocess via the following method:

           self._subprocess = subprocess.Popen(cmd, stdout=subprocess.PIPE, preexec_fn=os.setsid)

        This will allow us to attach a session id to the spawned child, allowing
        us to send a SIGTERM to the process on close