@Override
          public void run() throws Throwable {
            prf.compute("input".getBytes(UTF_8), 0);
          }
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