code: @Override
  	public String getMimeType() {
  		String contentType = backing.getContentType();
  
  		// IE6 (and apparently IE7) are broken and send the MIME type "image/pjpeg"
  		// regardless of whether the image is a progressive jpeg or not. Sending the
  		// incorrect MIME type back can cause display issues. It is always safe to
  		// change it to just be "image/jpeg".
  		if ("image/pjpeg".equals(contentType)) {
  			contentType = "image/jpeg";
  		}
  
  		return contentType;
  	}
docs: Returns the content type passed by the browser or <code>null</code> if not defined.
  
  @return The content type passed by the browser or <code>null</code> if not defined.