SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function arrayFold (children 1)
     ExpressionList (children 3)
      Function lambda (children 1)
       ExpressionList (children 2)
        Function tuple (children 1)
         ExpressionList (children 2)
          Identifier acc
          Identifier x
        Identifier x
      Literal \'not an array\'
      Function toUInt8 (children 1)
       ExpressionList (children 1)
        Literal UInt64_0
