@Test
  public void testComputePrf_identialToUnderlyingStreamingPrf() throws Exception {
    StreamingPrf streamer =
        new HkdfStreamingPrf(HashType.SHA1, "key0123456".getBytes(UTF_8), "salt".getBytes(UTF_8));
    PrfImpl prf = PrfImpl.wrap(streamer);

    byte[] prfImplOut = prf.compute("input".getBytes(UTF_8), 12);
    byte[] prfStreamerOut = new byte[12];
    streamer.computePrf("input".getBytes(UTF_8)).read(prfStreamerOut);

    assertThat(prfImplOut).isEqualTo(prfStreamerOut);
  }
Tests for HkdfPrf. Note that these tests rely on the tests for HkdfStreamingPrfTest to vet the
cryptographic gaurantees of Tink's PRF implementation. This class only tests the differences with
Prf.
java_src/src/test/java/com/google/crypto/tink/subtle/prf/PrfImplTest.java