SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function arrayConcat (children 1)
     ExpressionList (children 3)
      Literal Array_[NULL]
      Function emptyArrayUInt8 (children 1)
       ExpressionList
      Literal Array_[UInt64_1]
