* @param namespaces the namespace prefix and URIs to use
* @param headerName the name of the header to apply the expression to
* @return the builder to continue processing the DSL
*/
public T xpath(String text, Class<?> resultType, Namespaces namespaces, String headerName) {
XPathExpression expression = new XPathExpression(text);
expression.setResultType(resultType);
expression.setNamespaces(namespaces.getNamespaces());
expression.setHeaderName(headerName);
setExpressionType(expression);
return result;
}