class_docstr: It's like a dictionary, but it looks for items in the parent dictionary
code: def _keys(self):
      yielded = set()
      for k in self.keys():
          yielded.add(k)
          yield k
      if self.parent:
          for k in self.parent._keys():
              if k not in yielded:
                  yielded.add(k)
                  yield k
  
imports: from openpyxl.cell import cell
  from openpyxl.styles import Font, Alignment, PatternFill, NamedStyle, Border, Side, Color
  from openpyxl.styles.fills import FILL_SOLID
  from openpyxl.styles.numbers import FORMAT_CURRENCY_USD_SIMPLE, FORMAT_PERCENTAGE
  from openpyxl.styles.colors import BLACK
label_desc: Use image node_id 4 for calling the StyleDict obj's underlying member method code with example usage: obj._keys() without return types