How do I define a function based on compile definitions?

I’m having a hard time implementing a class that is using its update function only during editor time

import UnityEngine

[ExecuteInEditMode]
class EditorTime (MonoBehaviour):

    [SerializeField]
    private lastTestTime as single

    ifdef not UNITY_EDITOR:
        public def Test():
            lastTestTime = Time.time

        public def Update():
            Test()

I get this warning:

Assets/Meta/Scripts/EditorTime.boo(7,13): BCW0014: WARNING: Private field 'EditorTime.lastTestTime' is never used.

How do I properly remove such warnings?

Put the variable definition under the ifdef as well.

–Eric