pub unsafe extern "C" fn fdf_channel_read(
channel: fdf_handle_t,
options: u32,
out_arena: *mut *mut fdf_arena_t,
out_data: *mut *mut c_void,
out_num_bytes: *mut u32,
out_handles: *mut *mut zx_handle_t,
out_num_handles: *mut u32,
) -> zx_status_t