Add xhttp transport

common/xray/errors/errors.go

@@ -0,0 +1,25 @@
+package errors
+
+type hasInnerError interface {
+	// Unwrap returns the underlying error of this one.
+	Unwrap() error
+}
+
+func Cause(err error) error {
+	if err == nil {
+		return nil
+	}
+L:
+	for {
+		switch inner := err.(type) {
+		case hasInnerError:
+			if inner.Unwrap() == nil {
+				break L
+			}
+			err = inner.Unwrap()
+		default:
+			break L
+		}
+	}
+	return err
+}