code: public IAuthorizationPrincipal[] getAuthorizedPrincipals(
              String owner, String activity, String target) throws AuthorizationException {
          IPermission[] permissions = getPermissionsForOwner(owner, activity, target);
          return getPrincipalsFromPermissions(permissions);
      }
docs: Returns <code>IAuthorizationPrincipals</code> that have <code>IPermissions</code> for the
  given owner, activity and target.
  
  @return IAuthorizationPrincipal[]
  @param owner
  @param activity
  @param target