HashSet<String> namespaces = new HashSet<String>();
// guesstimate. Should avoid resizing too many times.
code_buffer = new StringBuilder(config_vars.size()*10);
for( int i = 0, size = config_vars.size(); i < size; ++i )
{
ConfigVar cv = config_vars.at(i);
if( !namespaces.contains(cv.ns) )
{
// If we haven't seen this namespace before, add a
// config namespace directive to make the namespace
// a configuration namespace.