Prove that trying to request with same title will fail (test_request_sameTitle).

Prove that shared parameter is correctly supported and system complains in case
if its type is incorrect (test_request_shared_True and test_request_shared_unsupported).

Prove that indexation will not result in damaged system (test_request_unindexed).

Prove that in case of normal request with same coordinates same instance is returned
(test_request_double).

Prove that in case if there is damage in system (same tree contains one then
more instance with same title) no more requests will be allowed (test_request_duplicated).