':param UUID dataset_id: The dataset UUID.
:param UUID node_id: The node UUID.
:param unicode action: The action that failed.'

def __init__(self, dataset_id, node_id, action):

    message = u'Cannot    {}    lease    {}    for    node    {}:    Lease    already    held    by    another    node'.format(action, unicode(dataset_id), unicode(node_id))
    return super(LeaseError, self).__init__(message)
