pub unsafe extern "C" fn igraph_trussness(
graph: *const igraph_t,
trussness: *mut igraph_vector_int_t,
) -> igraph_error_tpub unsafe extern "C" fn igraph_trussness(
graph: *const igraph_t,
trussness: *mut igraph_vector_int_t,
) -> igraph_error_t