code: def fontset_choice(arg):
      return directives.choice(
          arg, mathtext.MathTextParser._font_type_mapping
      )
  
imports: import hashlib
  from pathlib import Path
  from docutils import nodes
  from docutils.parsers.rst import Directive, directives
  import sphinx
  from sphinx.errors import ConfigError, ExtensionError
  import matplotlib
  from matplotlib import _api, mathtext
  from matplotlib.rcsetup import validate_float_or_None
label_desc: Use image node_id 1 for calling a global function with example usage: fontset_choice(arg) and returns: directives