'This method will take in a set of failing nodes, and toggle all of the nodes in the provided list to fail
writes.
@param failing_nodes A definitive list of nodes that should fail writes
@param keyspace The keyspace to enable failures on'

def setFailingNodes(self, failing_nodes, keyspace):

    for node in failing_nodes:
        if (node not in self.nodes_currently_failing):
            node.stop(wait_other_notice=True, gently=False)
            node.start(jvm_args=[('    -Dcassandra.test.fail_writes_ks=' + keyspace)], wait_for_binary_proto=True, wait_other_notice=True)
            self.nodes_currently_failing.append(node)
    for node in self.nodes_currently_failing:
        if (node not in failing_nodes):
            node.stop(wait_other_notice=True, gently=True)
            node.start(wait_for_binary_proto=True, wait_other_notice=True)
            self.nodes_currently_failing.remove(node)
