An access control entry defines the permissions of a user or group for a distinct resource.
Besides the CmsPermissionSet to define the permissions, the access control entry
contains the UUID of the resource and of the principal (user or group) who has the defined permissions.
An access control list contains the permission sets of all principals for a distinct resource
that are calculated on the permissions defined by various access control entries.
To each single resource, access control entries of type CmsAccessControlEntry can be assigned.
An access control entry defines the permissions (both allowed and explicitly denied) of a user or group for this resource.
By calling the method getAccessControlList the list is generated on the resource.