Function cpp_vm_object_write_user 

pub unsafe extern "C" fn cpp_vm_object_write_user(
    vmo: *mut VmObject,
    buffer: *const c_void,
    offset: u64,
    size: usize,
    options: u8,
    on_bytes_transferred: Option<unsafe extern "C" fn(ctx: *mut c_void, offset: u64, len: usize)>,
    on_bytes_transferred_ctx: *mut c_void,
    out_actual: *mut usize,
) -> zx_status_t