minimumLevel property
Events at or above this level are written; the rest are dropped at the sink rather than at each call site.
debug is excluded by default. A debug line is written to be read while
somebody is looking, and the file exists for the case where nobody was.
Settable, for the reason path is: an application typically keeps it in settings it reads after start-up, and a support request that needs verbose output is answered by changing it on a running app.
Implementation
TomDiagnosticLevel minimumLevel;