class_docstr: 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 HtmlLexer, XmlLexer
  from pygments.lexers.javascript import JavascriptLexer
  from pygments.lexers.css import CssLexer
  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
  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