func (c *ConfigFlag) Set(opt string) (err error) {
	parts := strings.SplitN(opt, ",", 2)
	key := parts[0]
	switch len(parts) {
	case 1:
		err = c.Config.Set(key, true)
	case 2:
		err = c.Config.Set(key, parts[1])
	}
	return
}
Set takes a comma separated value and follows the rules in Config.Set
using the first field as the option key, and the second (if present) as the value
package nsq
import (
	"strings"
)
type ConfigFlag struct {
	Config *Config
}