Debug writes output to os.Stderr with prefix 'debug'.

Debugf writes a line to os.Stderr with prefix 'debug', using fmt formatting options.

Debugln writes a line to os.Stderr with prefix `debug`, then ends with newline.

DebuglnMap prints each entry in `data` (every key in the map) on a new line.

DebuglnSlice prints each entry in `data` on a new line.

DebuglnSliceAsString prints each entry in `data` on a new line.

DebugReport logs a debug-level message in case the assertion does not hold.

Error writes a line to os.Stderr with prefix 'ERROR'.

Errorf writes a line to os.Stderr with prefix 'ERROR', using fmt formatting options.

Errorln writes a line to os.Stderr with prefix 'ERROR', closing with newline.

Info writes a line to os.Stderr with prefix 'info'.

Info writes a line to os.Stderr with prefix 'info'.

Infoln writes a line to os.Stderr with prefix 'info', closing with newline.

Warn writes a line to os.Stderr with prefix 'warn'.

Warn writes a line to os.Stderr with prefix 'warn'.

Warnln writes a line to os.Stderr with prefix 'warn', closing with newline.

WarnOnError checks for non-nil error, then prints warning message followed by error-message.