Debug starts a new message with debug level.

Err starts a new message with error level with err as a field if not nil or with info level if err is nil.

Error starts a new message with error level.

Fatal starts a new message with fatal level.

GetLogger get global log.

Info starts a new message with info level.

Panic starts a new message with panic level.

Print sends a log event using debug level and no extra field.

Printf sends a log event using debug level and no extra field.

SetLogger set global log.

Warn starts a new message with warn level.