code: @Nonnull
    public static ESuccess writeStream (@WillClose @Nonnull final OutputStream aOS, @Nonnull final byte [] aBuf)
    {
      return writeStream (aOS, aBuf, 0, aBuf.length);
    }
docs: Write bytes to an {@link OutputStream}.
  
  @param aOS
  The output stream to write to. May not be <code>null</code>. Is closed
  independent of error or success.
  @param aBuf
  The byte array to be written. May not be <code>null</code>.
  @return {@link ESuccess}