SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function arrayFirst (children 1)
     ExpressionList (children 2)
      Function lambda (children 1)
       ExpressionList (children 2)
        Function tuple (children 1)
         ExpressionList (children 1)
          Identifier x
        Function materialize (children 1)
         ExpressionList (children 1)
          Literal UInt64_1
      Literal Array_[UInt64_1, UInt64_2, UInt64_3]
