feat: implement Validate to check for cycle

examples/tasks/operations.go

@@ -3,6 +3,7 @@ package tasks
 import (
 	"context"
 
+	"github.com/oarkflow/errors"
 	"github.com/oarkflow/json"
 
 	"github.com/oarkflow/mq"
@@ -35,6 +36,7 @@ func (e *Condition) ProcessTask(ctx context.Context, task *mq.Task) mq.Result {
 	if err != nil {
 		panic(err)
 	}
+	return mq.Result{Error: errors.New("Condition error")}
 	switch email := data["email"].(type) {
 	case string:
 		if email == "abc.xyz@gmail.com" {