SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Literal UInt64_1
   ExpressionList (children 1)
    Function emptyArrayToSingle (children 1)
     ExpressionList (children 1)
      Function arrayFilter (children 1)
       ExpressionList (children 2)
        Function lambda (children 1)
         ExpressionList (children 2)
          Function tuple (children 1)
           ExpressionList (children 1)
            Identifier x
          Literal UInt64_1
        Function array (children 1)
         ExpressionList