kAttrQueryString
const char* kAttrQueryString = "_trk/qrystr";
ssize_t bytesRead = node.ReadAttrString(kAttrQueryString, &fPredicate);
file->WriteAttrString(kAttrQueryString, &predicate);
fStatus = modelNode->GetAttrInfo(kAttrQueryString, &info);
if (modelNode->ReadAttr(kAttrQueryString, B_STRING_TYPE, 0,