Unity rotation test

public class UnityApITest_1 : MonoBehaviour {
    

    // Quaternions are multiplied by vectors 

   public GameObject go;
   public GameObject resGo;
   public Vector3 euler;

    private void Update()
    {
    

        Debug.DrawLine(Vector3.zero, go.transform.position);
        Debug.DrawLine(Vector3.zero, resGo.transform.position);

        // Set the rotation 
        if (Input.GetKeyDown(KeyCode.A))
        {
    
            // Get the value of Quaternion 
            Quaternion qua = Quaternion.Euler(euler);
            // Four yuan number * Get the new position of the vector 
            Vector3 res = qua * go.transform.position;                      
            Debug.Log(" The result of quaternion multiplying vector is " + res);
            resGo.transform.position = res;
            // The change of one's own angle 
            resGo.transform.rotation = qua * go.transform.rotation;
        }

        // Look at the target object 
        if (Input.GetKeyDown(KeyCode.B))
        {
    
            // Suppose the target object is the origin 
            Vector3 dir = Vector3.zero - go.transform.position;
            go.transform.forward = dir.normalized;

        }

    }
    

}