Macro conditional_edges 

macro_rules! conditional_edges {
    ($graph:expr, $source:expr, $route_fn:expr, $($key:expr => $val:expr),+ $(,)?) => { ... };
}

Simplify add_conditional_edges with automatic route map construction.

Python:

graph.add_conditional_edges("chatbot", tools_condition)

Rust (before):

graph.add_conditional_edges(
    "chatbot",
    RoutingFn(tools_condition),
    Some({
        let mut map = HashMap::new();
        map.insert("tools".to_string(), "tools".to_string());
        map.insert(END.to_string(), END.to_string());
        map
    }),
)?;

Rust (after):

conditional_edges!(graph, "chatbot", tools_condition, "tools" => "tools", END => END)?;