'Retrieve a list of available snapshots (shadow copies) for *path*.
Note that snapshot features are only supported on Windows Vista Business, Enterprise and Ultimate, and on all Windows 7 editions.
:param string/unicode service_name: the name of the shared folder for the *path*
:param string/unicode path: path relative to the *service_name* where we are interested in the list of available snapshots
:return: A list of python *datetime.DateTime* instances in GMT/UTC time zone'

def listSnapshots(self, service_name, path, timeout=30):

    if (not self.sock):
        raise NotConnectedError('Not    connected    to    server')
    results = []
    def cb(entries):
        self.is_busy = False
        results.extend(entries)
    def eb(failure):
        self.is_busy = False
        raise failure
    self.is_busy = True
    try:
        self._listSnapshots(service_name, path, cb, eb, timeout=timeout)
        while self.is_busy:
            self._pollForNetBIOSPacket(timeout)
    finally:
        self.is_busy = False
    return results
