REGEXP_FILE
  RegExpPatternImpl: <(^*>
    RegExpBranchImpl: <(^*>
      RegExpGroupImpl: <(^*>
        PsiElement(GROUP_BEGIN)('(')
        RegExpPatternImpl: <^*>
          RegExpBranchImpl: <^*>
            RegExpClosureImpl: <^*>
              RegExpBoundaryImpl: <^>
                PsiElement(CARET)('^')
              RegExpQuantifierImpl: <*>
                PsiElement(STAR)('*')
        PsiErrorElement:')' expected
          <empty list>