pub unsafe extern "C" fn igraph_union_many(
res: *mut igraph_t,
graphs: *const igraph_vector_ptr_t,
edgemaps: *mut igraph_vector_int_list_t,
) -> igraph_error_tpub unsafe extern "C" fn igraph_union_many(
res: *mut igraph_t,
graphs: *const igraph_vector_ptr_t,
edgemaps: *mut igraph_vector_int_list_t,
) -> igraph_error_t