logger

type Logger interface {
	// SetField sets a field on the logger's context. All future messages on this logger
	// will have this field set.
	SetField(name string, value interface{})
	// Debug logs a debug message. If last parameter is a map[string]string, it's content
	// is added as fields to the message.
	Debug(v ...interface{})
	// Debug logs a debug message with format. If last parameter is a map[string]string,
	// it's content is added as fields to the message.
	Debugf(format string, v ...interface{})
	// Info logs a info message. If last parameter is a map[string]string, it's content
	// is added as fields to the message.
	Info(v ...interface{})
	// Info logs a info message with format. If last parameter is a map[string]string,
	// it's content is added as fields to the message.
	Infof(format string, v ...interface{})
	// Warn logs a warning message. If last parameter is a map[string]string, it's content
	// is added as fields to the message.
	Warn(v ...interface{})
	// Warn logs a warning message with format. If last parameter is a map[string]string,
	// it's content is added as fields to the message.
	Warnf(format string, v ...interface{})
	// Error logs an error message. If last parameter is a map[string]string, it's content
	// is added as fields to the message.
	Error(v ...interface{})
	// Error logs an error message with format. If last parameter is a map[string]string,
	// it's content is added as fields to the message.
	Errorf(format string, v ...interface{})
}