### Question:
VorbisUtil { public static int iLog(int x) { int val = 0; while (x > 0) { val++; x >>>= 1; } return val; } private  VorbisUtil(); static int iLog(int x); static VorbisIdHeader readVorbisIdentificationHeader(ParsableByteArray headerData); static CommentHeader readVorbisCommentHeader(ParsableByteArray headerData); static boolean verifyVorbisHeaderCapturePattern(int headerType, ParsableByteArray header,
      boolean quiet); static Mode[] readVorbisModes(ParsableByteArray headerData, int channels);  }### Answer:
@Test public void testILog() throws Exception { assertThat(iLog(0)).isEqualTo(0); assertThat(iLog(1)).isEqualTo(1); assertThat(iLog(2)).isEqualTo(2); assertThat(iLog(3)).isEqualTo(2); assertThat(iLog(4)).isEqualTo(3); assertThat(iLog(5)).isEqualTo(3); assertThat(iLog(8)).isEqualTo(4); assertThat(iLog(-1)).isEqualTo(0); assertThat(iLog(-122)).isEqualTo(0); }