try_activate_a2ui_extension

@require_optional_import(["a2a"], "a2a")
def try_activate_a2ui_extension(context: RequestContext) -> bool:
    """Activate the A2UI extension if the client requested it.

    Call this in your ``AgentExecutor`` to negotiate A2UI support.
    If the client's request includes the A2UI extension URI, it is
    activated and the function returns True.

    Args:
        context: The A2A request context.

    Returns:
        True if the A2UI extension was activated, False otherwise.
    """
    if A2UI_EXTENSION_URI in context.requested_extensions:
        # SDK 1.0 dropped `add_activated_extension`; we now signal activation
        # implicitly by acknowledging the requested extension via metadata.
        if context.metadata is None:
            context.metadata = {}
        activated = context.metadata.setdefault("activated_extensions", [])
        if A2UI_EXTENSION_URI not in activated:
            activated.append(A2UI_EXTENSION_URI)
        return True
    return False