'Find and run existing command with id in specified file.
SUBLIMEREPL_USER_DIR is consulted first, and then SUBLIMEREPL_DIR'

def run(self, id, file):

    for prefix in (SUBLIMEREPL_USER_DIR, SUBLIMEREPL_DIR):
        path = os.path.join(prefix, file)
        json_cmd = self._find_cmd(id, path)
        if json_cmd:
            break
    if (not json_cmd):
        return
    args = (json_cmd[u'args'] if (u'args' in json_cmd) else None)
    self.window.run_command(json_cmd[u'command'], args)
