Logging settings:
path— the path of the log.level— logging level.background— if true, then the log is duplicated in stdout.
Logging levels:
- 5 — all communications;
- 4 — all communications except DEBUG;
- 3 — not lower than WARNING;
- 2 — not lower than ERROR;
- 1 — CRITICAL only.
- 0 — disables logging.
