SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function materialize (alias arr) (children 1)
     ExpressionList (children 1)
      Literal Array_[UInt64_1, UInt64_2, UInt64_3]
   ExpressionList (children 1)
    Identifier arr.size0
