Function phytrace_builder_set_extensions_json 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn phytrace_builder_set_extensions_json(
    builder: *mut PhyTraceBuilderHandle,
    json_str: *const c_char,
) -> i32

Set arbitrary extensions on the builder as a JSON string.

This is used by the ROS2 generic converter to stash raw message payloads.

Parameters

• json_str — JSON object string, e.g. {"raw_msg": {...}}