digraph G {
                node [shape=record];
                rankdir=TB;
               IterSource_0 [label="{  IterSource |{<o0> output} }"];
IterSource_1 [label="{  IterSource |{<o0> output} }"];
Adder_2 [label="{ {<i0> input_a|<i1> input_b}| Adder |{<o0> output} }"];
Printer_3 [label="{ {<i0> input}| Printer  }"];

               IterSource_0:o0 -> Adder_2:i0 [label="usize"];
IterSource_1:o0 -> Adder_2:i1 [label="usize"];
Adder_2:o0 -> Printer_3:i0 [label="usize"];

            }