SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 2)
    Literal \'Enum8\'
    Function blockSerializedSize (children 1)
     ExpressionList (children 1)
      Function CAST (children 1)
       ExpressionList (children 2)
        Literal \'a\'
        Literal \'Enum8(\\\'a\\\' = 1, \\\'b\\\' = 2)\'
