REGEXP_FILE
  RegExpPatternImpl: <a[\t--]>
    RegExpBranchImpl: <a[\t--]>
      RegExpCharImpl: <a>
        PsiElement(CHARACTER)('a')
      RegExpClassImpl: <[\t--]>
        PsiElement(CLASS_BEGIN)('[')
        RegExpCharRangeImpl: <\t-->
          RegExpCharImpl: <\t>
            PsiElement(ESC_CTRL_CHARACTER)('\t')
          PsiElement(MINUS)('-')
          RegExpCharImpl: <->
            PsiElement(MINUS)('-')
        PsiElement(CLASS_END)(']')