'Returns `True` if we can get output of the command in the
`settings.wait_command` time.
Command will be killed if it wasn\'t finished in the time.
:type popen: Popen
:rtype: bool'

@staticmethod
def _wait_output(popen, is_slow):

    proc = Process(popen.pid)
    try:
        proc.wait((settings.wait_slow_command if is_slow else settings.wait_command))
        return True
    except TimeoutExpired:
        for child in proc.children(recursive=True):
            child.kill()
        proc.kill()
        return False
