// Set an empty MustUnderstand property on the data source
bads1.setProperty(SOAPHeaderBlock.MUST_UNDERSTAND_PROPERTY, null);
OMSourcedElement omse = soapFactory.createSOAPHeaderBlock(localName, ns, bads1);
soapHeader.addChild(omse);
OMNode firstChild = soapHeader.getFirstOMChild();
assertTrue("Expected OMSourcedElement child", firstChild instanceof SOAPHeaderBlock);
SOAPHeaderBlock child = (SOAPHeaderBlock) firstChild;
assertTrue("OMSourcedElement is expanded. This is unexpected", !child.isExpanded());
assertTrue("OMSourcedElement should be backed by a ByteArrayDataSource",