def unlink(self, node, hyperedge):
self.node_links[node].remove(hyperedge)<EOL>self.edge_links[hyperedge].remove(node)<EOL>self.graph.del_edge(((node,'<STR_LIT:n>'), (hyperedge,'<STR_LIT:h>')))<EOL>
Unlink given node and hyperedge.

@type  node: node
@param node: Node.

@type  hyperedge: hyperedge
@param hyperedge: Hyperedge.