@Test
public void fourBytesFromInt() {

    SignalUtil.fourBytesFromInt(0);
    byte[] a = {0,0,0,0};
    byte[] b = {0,0,0,5};
    byte[] c = {0,1,0,5};
    byte[] d = {2,1,0,5};
    assertTrue(Arrays.equals(a, SignalUtil.fourBytesFromInt(0)));
    assertTrue(Arrays.equals(b, SignalUtil.fourBytesFromInt(5)));
    int num = 0x00010005;
    byte[] ts = SignalUtil.fourBytesFromInt(num);
    assertTrue(Arrays.equals(c,ts));
    num = 0x02010005;
    ts = SignalUtil.fourBytesFromInt(num);
    assertTrue(Arrays.equals(d,ts));
}