The APIs for ContentService::loadContentListByContentInfo and ContentService::loadContent load list of internal fields without any order, which for PostgreSQL means it is random. This results in randomly failing integration tests. We execute them nightly, so the need to fix becomes important.

Possible ways to fix:
1. Introduce proper ordering for both mentioned API.
2. Do unordered assertion in test which fails (ref.: https://travis-ci.org/ezsystems/ezpublish-kernel/jobs/450304636#L909).

We should aim at the option 1. since we don't want our system to behave randomly. The option 2. is a workaround in case of a blocker (e.g. related to BC).