func (f Frame) String() string {
	return fmt.Sprintf("%s:%d %s", f.File, f.Line, f.Name)
}
String provides the standard file:line representation.
package stack
import (
	"bytes"
	"fmt"
	"os"
	"path/filepath"
	"runtime"
	"strings"
)
const maxStackSize = 32
type Frame struct {
	File string
	Line int
	Name string
}