anchor.diff:  stmt_attr_set(#prepare{}=X, ?STMT_ATTR_PREFETCH_ROWS, Value) ->
       X#prepare{prefetch_rows = Value}.
   
  --spec stmt_warning_count(prepare()) -> non_neg_integer().
  -stmt_warning_count(#prepare{result=R}) -> warning_count(R).
  +-spec stmt_warning_count(term()) -> non_neg_integer()|undefined.
  +stmt_warning_count(#prepare{result=R}) -> warning_count(R);
  +stmt_warning_count(_) -> undefined.
   
   %% == private ==
   
  
positive.code: 
  %% -- internal --
  -record(myer, {
            sup     :: pid(),
            worker  :: pid(),
            timeout :: timeout()
           }).
  
  -type(myer() :: #myer{}).
  
negative.code:             end
      end.
  
  -spec checkin(myer()) -> ok|{error,not_found|simple_one_for_one}.
  checkin(#myer{sup=S,worker=W})
    when is_pid(S), is_pid(W) ->
      true = unlink(W),
  