func Debugf(ctx context.Context, format string, args ...interface{}) {
	internal.Logf(ctx, 0, format, args...)
}
Debugf formats its arguments according to the format, analogous to fmt.Printf,
and records the text as a log message at Debug level. The message will be associated
with the request linked with the provided context.
package log
import (
	"golang.org/x/net/context"
	"google.golang.org/appengine/internal"
)