code: def _subsamplex(x, n):
      x = [
          F.get_item(xx, (slice(None, None, n), slice(None)))
          for xx in x
      ]
      ilens = [xx.shape[0] for xx in x]
      return x, ilens
  
label_desc: Use image node_id 1 for calling a global function with example usage: _subsamplex(x, n) and returns: x,  ilens