@Override
          protected int netWriteBufferSize() {
            return getAndUpdateSize(super.netWriteBufferSize(), netWriteBufSizeOverride, true);
          }
Replace the {@link #selector} instance with that overrides buffer sizing logic to induce BUFFER_OVERFLOW and
BUFFER_UNDERFLOW cases. This overrides the methods used to get the new size for the buffers used by
{@link javax.net.ssl.SSLEngine}, doubling the size of the buffer each time until the size recommended by the
engine is reached.
@param netReadBufSizeStart if non-null, initialize the net read buffer with this size.
@param netWriteBufSizeStart if non-null, initialize the net write buffer with this size.
@param appReadBufSizeStart if non-null, initialize the app buffer with this size.
ambry-network/src/test/java/com/github/ambry/network/SSLSelectorTest.java