The $properties property should be an associative array, with the structure below. Any options not set will be set to the default.
The table to retrieve preferences from. [preferences]
The field to use for matching user IDs. [user_id]
The field to use for matching preference names. [pref_name]
The field to retrieve preference values from. [pref_value]
The user ID to use for retrieving default values. [__default__]
The key to use for the cache in $_SESSION. [prefsCache]
Should values be cached for later use. [true]
Should values be serialized before saving to the database, and unserialized on retrieval. [false]
The DSN of the database connection to make, or a DB object.
An array of properties to set.
The default user to manage for.