code: def uniq_stable(elems):
      """uniq_stable(elems) -> list
  
      Return from an iterable, a list of all the unique elements in the input,
      but maintaining the order in which they first appear.
  
      Note: All elements in the input must be hashable for this routine
      to work, as it internally uses a set for efficiency reasons.
      """
      seen = set()
      return [x for x in elems if x not in seen and not seen.add(x)]
  
imports: from .py3compat import xrange
label_desc: Use image node_id 1 for calling a global function with example usage: uniq_stable(elems) and returns: unknown