REGEXP_FILE
  RegExpPatternImpl: <a\p{*}b>
    RegExpBranchImpl: <a\p{*}b>
      RegExpCharImpl: <a>
        PsiElement(CHARACTER)('a')
      RegExpClosureImpl: <\p{*>
        RegExpPropertyImpl: <\p{>
          PsiElement(PROPERTY)('\p')
          PsiElement(LBRACE)('{')
          PsiErrorElement:Property name expected
            <empty list>
        RegExpQuantifierImpl: <*>
          PsiElement(STAR)('*')
      RegExpCharImpl: <}>
        PsiElement(CHARACTER)('}')
      RegExpCharImpl: <b>
        PsiElement(CHARACTER)('b')