private static void setNamespaces( final XPath xpath, final Map<String,String> namespaces )
{
if ( namespaces == null )
return;
final XPathNamespaceContext namespaceContext = new XPathNamespaceContext();
for ( Entry<String, String> entry : namespaces.entrySet() )
namespaceContext.setMapping( entry.getKey(), entry.getValue() );
xpath.setNamespaceContext( namespaceContext );
}