IntModInv

        bool ok      = false;
    
        ok = IntModInv(&inverse, b, modulus);
        if (!ok) {
            IntDeinit(&inverse);

    }
    
    bool IntModInv(Int *result, const Int *value, const Int *modulus) {
        ValidateInt(result);
        ValidateInt(value);

    
    bool test_int_mod_inv(void) {
        WriteFmt("Testing IntModInv\n");
    
        DefaultAllocator alloc = DefaultAllocatorInit();

        Int check        = IntInit(&alloc.base);
    
        bool result = IntModInv(&result_value, &value, &mod);
        result      = result && (IntToU64(&result_value) == 4);

    
    bool test_int_mod_inv_no_solution(void) {
        WriteFmt("Testing IntModInv no-solution case\n");
    
        DefaultAllocator alloc = DefaultAllocatorInit();

        Int result_value = IntFrom(99, &alloc.base);
    
        bool result = !IntModInv(&result_value, &value, &mod);
        result      = result && (IntToU64(&result_value) == 99);