REGEXP_FILE
  RegExpPatternImpl: <a{3,3}>
    RegExpBranchImpl: <a{3,3}>
      RegExpClosureImpl: <a{3,3}>
        RegExpCharImpl: <a>
          PsiElement(CHARACTER)('a')
        RegExpQuantifierImpl: <{3,3}>
          PsiElement(LBRACE)('{')
          RegExpNumberImpl: <3>
            PsiElement(NUMBER)('3')
          PsiElement(COMMA)(',')
          RegExpNumberImpl: <3>
            PsiElement(NUMBER)('3')
          PsiElement(RBRACE)('}')