code: def fix_open_shift(
      gold_transition,
      pred_transition,
      gold_sequence,
      gold_index,
      root_labels,
  ):
      """
      Fix an Open replaced with a Shift
  
      Suppose we were supposed to guess NT_X and instead did S
  
      We derive the repair as follows.
  
      For simplicity, assume the open is not a unary for now
  
      Since we know an Open was legal, there must be stuff
        stuff NT_X
      Shift is also legal, so there must be other stuff and a previous Open
        stuff_1 NT_Y stuff_2 NT_X
      After the NT_X which we missed, there was a bunch of stuff and a close for NT_X
        stuff_1 NT_Y stuff_2 NT_X stuff_3 C
      There could be more stuff here which can be saved...
        stuff_1 NT_Y stuff_2 NT_X stuff_3 C stuff_4 C
        stuff_1 NT_Y stuff_2 NT_X stuff_3 C C
      """
      if not isinstance(gold_transition, OpenConstituent):
          return None
      if not isinstance(pred_transition, Shift):
          return None
  
      cur_index = gold_index
      cur_index = advance_past_unaries(gold_sequence, cur_index)
      if not isinstance(gold_sequence[cur_index], OpenConstituent):
          return None
      if gold_sequence[cur_index].top_label in root_labels:
          return None
      # cur_index now points to the NT_X we missed (not counting unaries)
  
      stuff_start = cur_index + 1
      # can't be a Close, since we just went past an Open and checked for unaries
      # can't be an Open, since two Open in a row is illegal
      assert isinstance(gold_sequence[stuff_start], Shift)
      stuff_end = advance_past_constituents(gold_sequence, stuff_start)
      # stuff_end is now the Close which ends NT_X
      cur_index = stuff_end + 1
      if cur_index >= len(gold_sequence):
          return None
      if isinstance(gold_sequence[cur_index], OpenConstituent):
          cur_index = advance_past_unaries(gold_sequence, cur_index)
          if cur_index >= len(gold_sequence):
              return None
      if isinstance(gold_sequence[cur_index], OpenConstituent):
          # an Open here signifies that there was a bracket containing X underneath Y
          # TODO: perhaps try to salvage something out of that situation?
          return None
      # the repair starts with the sequence up through the error,
      # then stuff_3, which includes the error
      # skip the Close for the missed NT_X
      # then finish the sequence with any potential stuff_4, the next Close, and everything else
      repair = (
          gold_sequence[:gold_index]
          + gold_sequence[stuff_start:stuff_end]
          + gold_sequence[cur_index:]
      )
      return repair
  
imports: from enum import Enum, auto
  from stanza.models.constituency.dynamic_oracle import DynamicOracle
  from stanza.models.constituency.parse_transitions import Shift, OpenConstituent, CloseConstituent
label_desc: Use image node_id 9 for calling a global function with example usage: fix_open_shift(gold_transition, pred_transition, gold_sequence, gold_index, root_labels) and returns: repair, None, None, None, None, None, None, None