REGEXP_FILE
  RegExpPatternImpl: <abcd*efg>
    RegExpBranchImpl: <abcd*efg>
      RegExpCharImpl: <a>
        PsiElement(CHARACTER)('a')
      RegExpCharImpl: <b>
        PsiElement(CHARACTER)('b')
      RegExpCharImpl: <c>
        PsiElement(CHARACTER)('c')
      RegExpClosureImpl: <d*>
        RegExpCharImpl: <d>
          PsiElement(CHARACTER)('d')
        RegExpQuantifierImpl: <*>
          PsiElement(STAR)('*')
      RegExpCharImpl: <e>
        PsiElement(CHARACTER)('e')
      RegExpCharImpl: <f>
        PsiElement(CHARACTER)('f')
      RegExpCharImpl: <g>
        PsiElement(CHARACTER)('g')