SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function equals (children 1)
     ExpressionList (children 2)
      Literal \'{ key: fn, value: concat }\'
      Function concat (children 1)
       ExpressionList (children 5)
        Literal \'{ key: \'
        Function toFixedString (children 1)
         ExpressionList (children 2)
          Literal \'fn\'
          Literal UInt64_2
        Literal \', value: \'
        Literal \'concat\'
        Literal \' }\'
