def generated_jison?
      return false unless extname == '.js'
      return false unless lines.count > 1
      return lines[0].start_with?("/* parser generated by jison ") ||
             lines[0].start_with?("/* generated by jison-lex ")
    end
def generated_jison?
      return false unless extname == '.js'
      return false unless lines.count > 1
      return lines[0].start_with?("/* parser generated by jison ") ||
             lines[0].start_with?("/* generated by jison-lex ")
    end
Internal: Is this a Jison-generated file?

 Jison-generated parsers typically contain:
 /* parser generated by jison
 on the first line.

 Jison-generated lexers typically contain:
 /* generated by jison-lex
 on the first line.

 Return true or false