fixed missing Differential

Brad Carman · Brad Carman · commit f2b44fb64452 · 2023-03-21T10:10:52.000-04:00
diff --git a/test/stream_connectors.jl b/test/stream_connectors.jl
@@ -374,6 +374,8 @@ function Pipe(; P, R, name)
 end
 
 function StaticVolume(; P, V, name)
+    D = Differential(t)
+
     pars = @parameters begin
         p_int = P
         vol = V
