@Test
public void testComputePrf_basic() throws Exception {

  HkdfStreamingPrf prf =
      new HkdfStreamingPrf(HashType.SHA1, "key0123456".getBytes(UTF_8), "salt".getBytes(UTF_8));
  InputStream input = prf.computePrf("input".getBytes(UTF_8));
  byte[] output = new byte[10];
  assertThat(input.read(output)).isEqualTo(10);
}