An invention claimed in a complete specification shall not be deemed to have been anticipated by reason only that at any time within one year before the priority date of the relevant claim of the specification, the invention was publicly worked in India--

(a) by the patentee or applicant for the patent or any person from whom he derives title; or

(b) by any other person with the consent of the patentee or applicant for the patent or any person from whom he derives title,

if the working was effected for the purpose of reasonable trial only and if it was reasonably necessary, having regard to the nature of the invention, that the working for that purpose should be effected in public.