1  
 2  program test.alpha {
 3      mapping map: u32 => u32;
 4  
 5      async transition main() -> Future {
 6          return finalize_main(1u32);
 7      }
 8  
 9      async function finalize_main(a:u32) {
10          if a == 1u32 {
11              let y: u32 = 1u32;
12              {
13                  // This is OK, but previously yielded an error.
14                  y = 2u32;
15              }
16              map.set(y, y);
17          }
18      }
19  }