XProcData data = runtime.getXProcData();
data.openFrame(this);
runtime.start(this);
try {
xstep.run();
// FIXME: Is it sufficient to only do this for atomic steps?
String cache = getInheritedExtensionAttribute(XProcConstants.cx_cache);
if ("true".equals(cache)) {
for (String port : outputs.keySet()) {