coveragesPart.setHeader("Content-Type", "text/xml");
multipart.addBodyPart(coveragesPart);
// the actual coverage
BodyPart coveragePart = new MimeBodyPart();
delegate.prepare(outputFormat, coverage);
coveragePart.setDataHandler(new DataHandler(delegate, "geoserver/coverageDelegate"));
coveragePart.setHeader("Content-ID", "<theCoverage>");
coveragePart.setHeader("Content-Type", delegate.getContentType());
coveragePart.setHeader("Content-Transfer-Encoding", "base64");
multipart.addBodyPart(coveragePart);