Relying on UUID::__toString() now triggers a notice, causing
unrelated patches to fail. This patch addresses the issue.
Change-Id: Ia94826a0e600adf8afd5908af75772b596ab8d0a
The test suite sets up various mocks for Flow classes and inserts
them into Flow\Container, so the API module retrieves the correct
mock classes instead.
Change-Id: I9c5e910e288f3dd72c66e68ca558265b8ca8ce5e