PermissionsHash() 
{
        permsMap = new HashMap< Permission, Permission >(11);
}

Create an empty PermissionsHash object.

 public  void add(Permission permission) 
{
        synchronized (this) {
            permsMap.put(permission, permission);
        }
}

Adds a permission to the PermissionsHash.

 public Enumeration<Permission> elements() 
{
        // Convert Iterator of Map values into an Enumeration
        synchronized (this) {
            return Collections.enumeration(permsMap.values());
        }
}

Returns an enumeration of all the Permission objects in the container.

 public boolean implies(Permission permission) 
{
        // attempt a fast lookup and implies. If that fails
        // then enumerate through all the permissions.
        synchronized (this) {
            Permission p = permsMap.get(permission);
            // If permission is found, then p.equals(permission)
            if (p == null) {
                for (Permission p_ : permsMap.values()) {
                    if (p_.implies(permission))
                        return true;
                }
                return false;
            } else {
                return true;
            }
        }
}

Check and see if this set of permissions implies the permissions expressed in "permission".