class_docstr: A Scheme lexer.
  
  This parser is checked with pastes from the LISP pastebin
  at http://paste.lisp.org/ to cover as much syntax as possible.
  
  It supports the full Scheme syntax as defined in R5RS.
  
  .. versionadded:: 0.6
code: def get_tokens_unprocessed(self, text):
      for index, token, value in super().get_tokens_unprocessed(text):
          if token is Name.Function or token is Name.Variable:
              if value in scheme_keywords:
                  yield index, Keyword, value
              elif value in scheme_builtins:
                  yield index, Name.Builtin, value
              else:
                  yield index, token, value
          else:
              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 1 for calling the SchemeLexer obj's underlying member method code with example usage: obj.get_tokens_unprocessed(text) without return types