<prompt> Translate the following text to EnglishKatika kesi kama hizo, ombi la Huduma lazima liunge mkono na ushuhuda wa shahidi wa Huduma ya Posta ambaye anaelezea sababu ya kipindi cha majaribio cha miaka mingi kilichopendekezwa.  <response>: In such instances, the Services request must be supported by testimony of a Postal Service witness that explains the rationale for the proposed multi-year test period. 