REGEXP_FILE
  RegExpPatternImpl: <a([bc]+)(c*d)>
    RegExpBranchImpl: <a([bc]+)(c*d)>
      RegExpCharImpl: <a>
        PsiElement(CHARACTER)('a')
      RegExpGroupImpl: <([bc]+)>
        PsiElement(GROUP_BEGIN)('(')
        RegExpPatternImpl: <[bc]+>
          RegExpBranchImpl: <[bc]+>
            RegExpClosureImpl: <[bc]+>
              RegExpClassImpl: <[bc]>
                PsiElement(CLASS_BEGIN)('[')
                RegExpCharImpl: <b>
                  PsiElement(CHARACTER)('b')
                RegExpCharImpl: <c>
                  PsiElement(CHARACTER)('c')
                PsiElement(CLASS_END)(']')
              RegExpQuantifierImpl: <+>
                PsiElement(PLUS)('+')
        PsiElement(GROUP_END)(')')
      RegExpGroupImpl: <(c*d)>
        PsiElement(GROUP_BEGIN)('(')
        RegExpPatternImpl: <c*d>
          RegExpBranchImpl: <c*d>
            RegExpClosureImpl: <c*>
              RegExpCharImpl: <c>
                PsiElement(CHARACTER)('c')
              RegExpQuantifierImpl: <*>
                PsiElement(STAR)('*')
            RegExpCharImpl: <d>
              PsiElement(CHARACTER)('d')
        PsiElement(GROUP_END)(')')