The legacy driver would return a comma-delimited list of host:port combinations; however, that would require __toString() to invoke topology discovery on new Manager instances. Returning the URI is less invasive.

See: PHPC-465, HHVM-129

See: PHPC-444, HHVM-117

Versions of MongoDB before 3.0 create a database when dropping the collection of a database that doesn't exist (as is done by the setUp() method).

Options can be passed directly to FindAndModify after any necessary translation/conversion.