CLean up

Author: sharanry

src/systems/discrete_system/discrete_system.jl

@@ -186,7 +186,6 @@ function generate_function(
     eqs = equations(sys)
     foreach(check_difference_variables, eqs)
     # substitute x(t) by just x
-    # rhss = [isdifference(eq.lhs) ? arguments(eq.lhs)[1] + eq.rhs : eq.rhs for eq in eqs]
     rhss = [eq.rhs for eq in eqs]
 
     u = map(x->time_varying_as_func(value(x), sys), dvs)