Finish all draft v3 pointer collector tests

Signed-off-by: Francis Galiegue <fgaliegue@gmail.com>
Start to test SchemaWalker mechanics

Signed-off-by: Francis Galiegue <fgaliegue@gmail.com>
SchemaWalkerTest: test that a new tree is processed when returned

Signed-off-by: Francis Galiegue <fgaliegue@gmail.com>