test: update bankindex test

test/Python/src/federated/BankIndex.lf

@@ -1,11 +1,28 @@
 target Python
 
 reactor A(bank_index=0) {
- reaction(startup) {=
+ output out
+
+ reaction(startup) -> out {=
  print("bank_index: {:d}".format(self.bank_index))
+ out.set(self.bank_index)
+ =}
+}
+
+reactor B(STA = 1 s) {
+ input[4] inp
+
+ reaction(inp) {=
+ for i, port in enumerate(inp):
+ assert port.is_present
+ print("in[{:d}]: {:d}".format(i, port.value))
+ assert port.value == i
+ request_stop()
  =}
 }
 
 federated reactor {
  a = new[4] A()
+ b = new B()
+ a.out -> b.inp
 }