Decorator which specifies that a user must have all the specified roles.
    Example::

        @app.route('/dashboard')
        @roles_required('admin', 'editor')
        def dashboard():
            return 'Dashboard'

    The current user must have both the `admin` role and `editor` role in order
    to view the page.

    :param args: The required roles.

def roles_required(*roles):
    """Decorator which specifies that a user must have all the specified roles.
    Example::

        @app.route('/dashboard')
        @roles_required('admin', 'editor')
        def dashboard():
            return 'Dashboard'

    The current user must have both the `admin` role and `editor` role in order
    to view the page.

    :param args: The required roles.
    """
    def wrapper(fn):
        @wraps(fn)
        def decorated_view(*args, **kwargs):
            perms = [Permission(RoleNeed(role)) for role in roles]
            for perm in perms:
                if not perm.can():
                    if _security._unauthorized_callback:
                        return _security._unauthorized_callback()
                    else:
                        return _get_unauthorized_view()
            return fn(*args, **kwargs)
        return decorated_view
    return wrapper