code: public InputStream tryGetInputStream(HttpServletRequest request, MutableObject<byte[]> sourceMapResult) throws IOException {
  		InputStream result = null;
  		// Check bytes before filename when reading and reverse order when setting
  		if (bytes != null || filename != null) {
  			try {
  				result = getInputStream(request, sourceMapResult);
  			} catch (Exception e) {
  				if (LayerImpl.log.isLoggable(Level.SEVERE)) {
  					LayerImpl.log.log(Level.SEVERE, e.getMessage(), e);
  				}
  				// just return null
  			}
  		}
  		return result;
  	}
docs: Can fail by returning null, but won't throw an exception.
  
  @param request
  the request object
  @param sourceMapResult
  (Output) mutable object reference to the source map.  May be null
  if source maps are not being requested.
  @return The LayerInputStream, or null if data is not available
  @throws IOException