func IsTag(key string) (string, bool) {
	return "", false
}
IsTag checks if key is tag. This is always false.
package blue
import (
	"strings"
	"time"
)
func joinkey(a, b string) string {
	if a != "" {
		return a + "_" + b
	}
	return b
}
func IsTimeStamp(key string, value interface{}) (time.Time, bool) {
	if key == "" {
		return time.Time{}, false
	}
	low := strings.ToLower(key)
	if low == "timestamp" {
		if ns, ok := value.(float64); ok {
			return time.Unix(0, int64(ns)), true
		}
	}
	return time.Time{}, false
}