Symfony version(s) affected: 4.3

Description
RoleHierarchyInterface doesn't contain any methods.

Comment said "The getReachableRoles(Role[] $roles) method that returns an array of all reachable Role objects is deprecated
since Symfony 4.3."
And we should use method "getReachableRoleNames" or something else.

BUT RoleHierarchyInterface is empty.
I couldn't make a mock from it.