REGEXP_FILE
  RegExpPatternImpl: <a*>
    RegExpBranchImpl: <a*>
      RegExpClosureImpl: <a*>
        RegExpCharImpl: <a>
          PsiElement(CHARACTER)('a')
        RegExpQuantifierImpl: <*>
          PsiElement(STAR)('*')
          PsiErrorElement:Dangling quantifier '*'
            <empty list>
  PsiElement(STAR)('*')