docstr: *valid* is a list of legal strings.
code: def __init__(
      self, key, valid, ignorecase=False, *, _deprecated_since=None
  ):
      """*valid* is a list of legal strings."""
      self.key = key
      self.ignorecase = ignorecase
      self._deprecated_since = _deprecated_since
  
      def func(s):
          if ignorecase:
              return s.lower()
          else:
              return s
  
      self.valid = {func(k): k for k in valid}
  
imports: import ast
  from functools import lru_cache, reduce
  from numbers import Real
  import operator
  import os
  import re
  import numpy
  from matplotlib import _api, cbook
  from matplotlib.cbook import ls_mapper
  from matplotlib.colors import Colormap, is_color_like
  from matplotlib._fontconfig_pattern import parse_fontconfig_pattern
  from matplotlib._enums import JoinStyle, CapStyle
  from cycler import Cycler, cycler
label_desc: Use image node_id 1 to create a new ValidateInStrings object  with example: obj = ValidateInStrings(key, valid, ignorecase)