Add some todos, add issame and caninteract to module instead of test

test/unit_tests_qedmodel.jl

@@ -1,6 +1,8 @@
 using MetagraphOptimization
 using QEDbase
 
+import MetagraphOptimization.caninteract
+import MetagraphOptimization.issame
 import MetagraphOptimization.interaction_result
 import MetagraphOptimization.propagation_result
 import MetagraphOptimization.direction
@@ -25,30 +27,6 @@ testparticleTypesPropagated = [
     AntiFermionStateful{Incoming},
 ]
 
-function caninteract(t1::Type{<:QEDParticle}, t2::Type{<:QEDParticle})
-    if (t1 == t2)
-        return false
-    end
-    if (t1 <: PhotonStateful && t2 <: PhotonStateful)
-        return false
-    end
-
-    for (p1, p2) in [(t1, t2), (t2, t1)]
-        if (p1 == FermionStateful{Incoming} && p2 == AntiFermionStateful{Outgoing})
-            return false
-        end
-        if (p1 == FermionStateful{Outgoing} && p2 == AntiFermionStateful{Incoming})
-            return false
-        end
-    end
-
-    return true
-end
-
-function issame(t1::Type{<:QEDParticle}, t2::Type{<:QEDParticle})
-    return !caninteract(t1, t2)
-end
-
 @testset "Interaction Result" begin
     for p1 in testparticleTypes, p2 in testparticleTypes
         if !caninteract(p1, p2)