func Panic(t *testing.T, fn func(), matches string) {
	if x := doesPanic(2, fn, matches); x != "" {
		fmt.Println(x)
		t.Fail()
	}
}
Panic asserts that function fn() panics.
It assumes that recover() either returns a string or
an error and fails if the message does not match
the regular expression in 'matches'.
package assert
import (
	"fmt"
	"path/filepath"
	"reflect"
	"regexp"
	"runtime"
	"strings"
	"testing"
)
const skip = 2
func Equal(t *testing.T, got, want interface{}, msg ...string) {
	if x := equal(2, got, want, msg...); x != "" {
		fmt.Println(x)
		t.Fail()
	}
}
func equal(skip int, got, want interface{}, msg ...string) string {
	if !reflect.DeepEqual(got, want) {
		return fail(skip, "got %v want %v %s", got, want, strings.Join(msg, " "))
	}
	return ""
}