Constant DEFAULT_GROUP_CHAT_MAX_ITERATIONS 

pub const DEFAULT_GROUP_CHAT_MAX_ITERATIONS: usize = 40; // 40usize

Safety bound on manager rounds applied by GroupChatBuilder when no explicit max_rounds is configured.

Python leaves manager rounds unbounded (capped only by the workflow’s DEFAULT_MAX_ITERATIONS = 100); this Rust default prevents an unbounded round-robin or LLM manager from looping forever.