public int getTagSizeBytes() {
    return tagSizeBytes;
  }
The tag size accepts values between 0 and 16 bytes. However, some implementation may not
support the full set of parameters at the moment and may restrict the tag size to a fixed
value (i.e. 16 bytes).
java_src/src/main/java/com/google/crypto/tink/aead/AesEaxParameters.java