func (l *StdLogger) Errorln(args ...interface{}) {
	fmt.Fprintln(l.errStream, args...)
}
Errorln prints an formatted error message
using fmt.Fprintln function
package logging
import (
	"fmt"
	"io"
	"os"
)
type StdLoggerBuilder struct {
	debugEnabled bool
	infoEnabled  bool
	errorEnabled bool
	outStream    io.Writer
	errStream    io.Writer
}
type StdLogger struct {
	debugEnabled bool
	infoEnabled  bool
	errorEnabled bool
	outStream    io.Writer
	errStream    io.Writer
}
func NewStdLoggerBuilder() *StdLoggerBuilder {
	builder := new(StdLoggerBuilder)
	builder.debugEnabled = false
	builder.infoEnabled = true
	builder.errorEnabled = true
	return builder
}
func (b *StdLoggerBuilder) Streams(out io.Writer, err io.Writer) *StdLoggerBuilder {
	b.outStream = out
	b.errStream = err
	return b
}
func (b *StdLoggerBuilder) Debug(flag bool) *StdLoggerBuilder {
	b.debugEnabled = flag
	return b
}
func (b *StdLoggerBuilder) Info(flag bool) *StdLoggerBuilder {
	b.infoEnabled = flag
	return b
}
func (b *StdLoggerBuilder) Error(flag bool) *StdLoggerBuilder {
	b.errorEnabled = flag
	return b
}
func (l *StdLogger) DebugEnabled() bool {
	return l.debugEnabled
}
func (l *StdLogger) InfoEnabled() bool {
	return l.infoEnabled
}
func (l *StdLogger) ErrorEnabled() bool {
	return l.errorEnabled
}
func (b *StdLoggerBuilder) Build() (logger *StdLogger, err error) {
	logger = new(StdLogger)
	logger.debugEnabled = b.debugEnabled
	logger.infoEnabled = b.infoEnabled
	logger.errorEnabled = b.errorEnabled
	logger.outStream = b.outStream
	logger.errStream = b.errStream
	if logger.outStream == nil {
		logger.outStream = os.Stdout
	}
	if logger.errStream == nil {
		logger.errStream = os.Stderr
	}
	return
}
func (l *StdLogger) Info(args ...interface{}) {
	fmt.Fprint(l.outStream, args...)
}
func (l *StdLogger) Infof(format string, args ...interface{}) {
	fmt.Fprintf(l.outStream, format, args...)
}
func (l *StdLogger) Infoln(args ...interface{}) {
	fmt.Fprintln(l.outStream, args...)
}
func (l *StdLogger) Error(args ...interface{}) {
	fmt.Fprint(l.errStream, args...)
}
func (l *StdLogger) Errorf(format string, args ...interface{}) {
	fmt.Fprintf(l.errStream, format, args...)
}