protected boolean opaqueIsValid() {
    if (responseOpaque != opaque) {
      getLogger().warn("Expected opaque:  %d, got opaque:  %d\n",
          responseOpaque, opaque);
    }
    return responseOpaque == opaque;
  }
Validate an opaque value from the header. This may be overridden from a
subclass where the opaque isn't expected to always be the same as the
request opaque.
src/main/java/net/spy/memcached/protocol/binary/OperationImpl.java