// unittest
TEST(ProcessDataTest, HandlesNegativeValue) {
    EXPECT_EQ(-1, process_data(-5));
}

TEST(ProcessDataTest, HandlesValueLessThanOrEqualTo10) {
    EXPECT_EQ(15, process_data(5));
}

TEST(ProcessDataTest, HandlesValueGreaterThan10) {
    EXPECT_EQ(30, process_data(15));
}
