@Test
void checkHighUsage() {

    stats.checkHighUsage(0.7, 0.8, "disk");
    assertThat(stats.errorCode).isNull();
    stats.checkHighUsage(0.8, 0.8, "disk");
    assertThat(stats.errorCode).isEqualTo("HIGH_DISK_USAGE");
    assertThat(stats.errorMessage).isEqualTo("disk usage is too high, usage=80%");
}