return null;
return Collections.emptySet();  Set<MPartInfo> bodies = null;
    public static MPartInfo getBody(List parts, boolean preferHtml) {     	if (parts.isEmpty())     		return null;     	     	// if top-level has no children, then it is the body     	MPartInfo top = (MPartInfo) parts.get(0);     	if (!top.getContentType().startsWith(CT_MULTIPART_PREFIX))     		return top.getDisposition().equals(Part.ATTACHMENT) ? null : top;        return getBodySubpart(top, preferHtml);    }