Const levelMapper
levelMapper: object
[`${Level.DEBUG}`]
[`${Level.DEBUG}`]: string = "debug"
[`${Level.ERROR}`]
[`${Level.ERROR}`]: string = "error"
[`${Level.INFO}`]
[`${Level.INFO}`]: string = "info"
[`${Level.WARN}`]
[`${Level.WARN}`]: string = "warn"