class_docstr: Lexer for the TeX and LaTeX typesetting languages.
class_docstr_tok: ["Lexer","for","the","TeX","and","LaTeX","typesetting","languages","."]
code: def analyse_text(text):
      for start in (
          "\\documentclass",
          "\\input",
          "\\documentstyle",
          "\\relax",
      ):
          if text[: len(start)] == start:
              return True
  
imports: import re
  from pygments.lexers.html import XmlLexer
  from pygments.lexers.javascript import JavascriptLexer
  from pygments.lexers.css import CssLexer
  from pygments.lexers.lilypond import LilyPondLexer
  from pygments.lexers.data import JsonLexer
  from pygments.lexer import RegexLexer, DelegatingLexer, include, bygroups, using, this, do_insertions, default, words
  from pygments.token import Text, Comment, Operator, Keyword, Name, String, Number, Punctuation, Generic, Other, Whitespace
  from pygments.util import get_bool_opt, ClassNotFound
label_desc: Use image node_id 1 for calling the TexLexer obj's underlying member method code with example usage: obj.analyse_text(text) and returns: True