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)\'