'Private helper that abstracts the use of ctypes.
Calls the internal inotify API to remove an fd from inotify then
removes the corresponding watchpoint from the internal mapping together
with the file descriptor from the watchpath.'

def _rmWatch(self, wd):

    self._inotify.remove(self._fd, wd)
    iwp = self._watchpoints.pop(wd)
    self._watchpaths.pop(iwp.path)
