code: def processHintmask(self, index):
      cs = self.callingStack[-1]
      hints = cs._hints
      hints.has_hintmask = True
      if hints.status != 2:
          # Check from last_check, see if we may be an implicit vstem
          for i in range(hints.last_checked, index - 1):
              if isinstance(cs.program[i], str):
                  hints.status = 2
                  break
          else:
              # We are an implicit vstem
              hints.has_hint = True
              hints.last_hint = index + 1
              hints.status = 0
      hints.last_checked = index + 1
  
imports: from fontTools.misc import psCharStrings
  from fontTools import ttLib
  from fontTools.pens.basePen import NullPen
  from fontTools.misc.roundTools import otRound
  from fontTools.misc.loggingTools import deprecateFunction
  from fontTools.subset.util import _add_method, _uniq_sort
label_desc: Use image node_id 11 for calling the _DehintingT2Decompiler obj's underlying member method code with example usage: obj.processHintmask(index) without return types