Access a class from Editor script? (Visual Studio)

I followed this unity docs tutorial:

Placed DrawLineEditor within Editor folder. Placed DrawLine outside of Editor folder. Attached DrawLine to a GameObject, added some GameObjects to scene and registered them in DrawLine script via inspector. In unity, everything shows correctly.

After i opened the DrawLineEditor in VisualStudio, the VS reports error:
CS0246 The type or namespace name ‘DrawLine’ could not be found (are you missing a using directive or an assembly reference?)

and all istances of “DrawLine” are red-underlined, showing error. How do i fix this in VisualStudio so that it recognizes “DrawLine” outside of the Editor folder? Namespaces dont seem to work either.

nwm! moved the DrawLineEditor out of “Editor” folder and back again a few times and “VS fixed itself”.