class_docstr: Lexer for Shen source code.
  
  .. versionadded:: 2.1
code: def _process_symbols(self, tokens):
      opening_paren = False
      for index, token, value in tokens:
          if opening_paren and token in (Literal, Name.Variable):
              token = self.MAPPINGS.get(value, Name.Function)
          elif token == Literal and value in self.BUILTINS_ANYWHERE:
              token = Name.Builtin
          opening_paren = value == "(" and token == Punctuation
          yield index, token, value
  
imports: import re
  from pygments.lexer import RegexLexer, include, bygroups, words, default
  from pygments.token import Text, Comment, Operator, Keyword, Name, String, Number, Punctuation, Literal, Error, Whitespace
  from pygments.lexers.python import PythonLexer
  from pygments.lexers._scheme_builtins import scheme_keywords, scheme_builtins
label_desc: Use image node_id 4 for calling the ShenLexer obj's underlying member method code with example usage: obj._process_symbols(tokens) without return types