pub unsafe extern "C" fn lv_tree_walk(
node: *const _lv_tree_node_t,
mode: u8,
cb: Option<unsafe extern "C" fn(*const _lv_tree_node_t, *mut c_void) -> bool>,
bcb: Option<unsafe extern "C" fn(*const _lv_tree_node_t, *mut c_void) -> bool>,
acb: Option<unsafe extern "C" fn(*const _lv_tree_node_t, *mut c_void)>,
user_data: *mut c_void,
) -> bool