REGEXP_FILE
  RegExpPatternImpl: <{1,2}>
    RegExpBranchImpl: <{1,2}>
      PsiErrorElement:Unexpected start of quantifier '{'
        <empty list>
      PsiElement(LBRACE)('{')
      PsiElement(NUMBER)('1')
      PsiElement(COMMA)(',')
      PsiElement(NUMBER)('2')
      PsiElement(RBRACE)('}')