public Document toDOM(java.io.Serializable structure) {
		RegularExpression re = (RegularExpression) structure;
		Document doc = newEmptyDocument();
		Element se = doc.getDocumentElement();
		// Add the regular expression tag.
		se.appendChild(createComment(doc, COMMENT_EXPRESSION));
		se
				.appendChild(createElement(doc, EXPRESSION_NAME, null, re
						.asString()));
		// Return the completed document.
		return doc;
	}