Improved error handling in vchasno responses

api/responses.go

@@ -15,6 +15,17 @@ type BaseResponse struct {
 	ErrorExtra interface{} `json:"error_extra"`
 }
 
+func (r *BaseResponse) HasError() bool {
+	return r.Res != 0
+}
+
+func (r *BaseResponse) Error() string {
+	if r.Errortxt != "" {
+		return r.Errortxt
+	}
+	return ""
+}
+
 type SellResponse struct {
 	BaseResponse
 	Info SellInfo `json:"info"`