SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Literal \'FixedString(32)\'
    Function blockSerializedSize (children 1)
     ExpressionList (children 1)
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal \'foo\'
        Literal \'FixedString(32)\'