'Test that a crawl is requested if the signer cannot validate the previous hash of a request'

def test_crawl_on_partial(self):

    (node, other, another) = self.create_nodes(3)
    TestTrustChainCommunity.create_block(node, other, self._create_target(node, other), {'id': 42})
    node.call(node.community.sign_block, self._create_target(node, another), another.my_member.public_key, {'id': 42})
    another.give_message(another.receive_message(names=[HALF_BLOCK]).next()[1], node)
    message = node.receive_message(names=[CRAWL]).next()[1]
    self.assertTrue(message)
