SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Literal \'Nullable(UInt64)\'
    Function blockSerializedSize (children 1)
     ExpressionList (children 1)
      Function toNullable (children 1)
       ExpressionList (children 1)
        Literal UInt64_244837809905325
