@Theory
  public void testEncryptSingleBytes(
      @FromDataPoints("singleBytesTestVectors") AesGcmHkdfStreamingTestVector t) throws Exception {
    StreamingTestUtil.testEncryptSingleBytes(t.directConstructorAgs, t.plaintextSize);
  }
Encrypt and then decrypt partially, and check that the result is the same.
java_src/src/test/java/com/google/crypto/tink/subtle/AesGcmHkdfStreamingTest.java