public static DocumentBuilder getDocumentBuilder(String implementation, ClassLoader classLoader) {
        return getDocumentBuilder(true);
    }
Creates a new XML DocumentBuilder.

@param implementation which jaxp implementation should be used
@param classLoader which class loader should be used when getting a new DocumentBuilder
@throws RuntimeException if we fail to create one
@return a DocumentBuilder
vespajlib/src/main/java/com/yahoo/text/XML.java