More comments

So if the source vector is being updated every time step, it might be
"easy" to implement these things.

src/modules/solver/electromagnetic/moduleEM.f90

@@ -49,7 +49,7 @@ MODULE moduleEM
 
       END DO
 
-    END SUBROUTINE
+    END SUBROUTINE apply
 
     !Assemble the source vector based on the charge density to solve Poisson's equation
     SUBROUTINE assembleSourceVector(vectorF)
@@ -130,6 +130,7 @@ MODULE moduleEM
       ALLOCATE(tempF(1:mesh%numNodes))
       !$OMP END SINGLE
 
+      !TODO: Is this done every time step??? Then things are gonna be really simple.
       CALL assembleSourceVector(tempF)
 
       !$OMP SINGLE