Can't collect Class in a Namespace from another class C#


So I have GameObject A and GameObject B. Game Object A and B both have scripts on them. Usually, I can collect Object A’s script from Object B’s script like this

ObjectAClass objectAClass = objectA.GetComponent<ObjectAClass>();

The problem his, I am trying to collect a class from someone else who has enclosed it in a namespace like this.

On Object A:

namespace ThisNameSpace
     public class ObjectAClass : MonoBehaviour
          // Object A class

Now if I am in the script in object b, I can no longer call that Object A’s Class

On Object B:

ObjectAClass objectAClass = objectA.GetComponent<ObjectAClass>();
// No longer works.

Why is that? How can I now make a variable of the class from another object.

Thank you for reading.

After searching some more after asking the question I found the answer.

On ObjectB you have to add the line:

using ThisNameSpace

Same as if you wanted to use List instead of arrays and you use

using System.Collections.Generic

I will leave this up incase someone else runs into this problem.

Thank you.