Function print_result 

pub fn print_result(result: &Value)

Print the last AI message from an invoke / ainvoke result.

Mirrors print_stream for non-streaming scenarios. Finds the last AI message in the {"messages": [...]} state, prints its thinking (if any) in dim gray followed by the content in normal color.

Example

let result = agent.ainvoke(&input, &RunnableConfig::new()).await?;
print_result(&result);