Information about the Resource to which the given Group may have been granted access.
Access Modes per Group that have been explicitly granted for the given Resource, or null if it could not be determined (e.g. because the current user does not have Control Access to a given Resource or its Container).
Returns all explicitly-granted Access Modes per Group for the given Resource.
The function does not return Access Modes granted indirectly to the Group through other ACL rules, e.g., public permissions.