'Test crawl without a block.'

def test_crawl_no_block(self):

    (node, crawler) = self.create_nodes(2)
    TestTrustChainCommunity.crawl_node(crawler, node, self._create_target(crawler, node))
    self.assertBlocksInDatabase(node, 0)
    self.assertBlocksInDatabase(crawler, 0)
