1  
 2  program test.alpha {
 3  
 4      mapping balances: address => u32;
 5  
 6      async transition foo() -> Future {
 7          return finalize_foo(self.caller);
 8      }
 9  
10      async function finalize_foo(account: address) -> () {
11          Mapping::set(balances, account, 1u32);
12  
13          let expect_true: bool = Mapping::contains(balances, account);
14          assert(expect_true);
15  
16          Mapping::remove(balances, account); // Remove the mapping entry for account
17  
18          let expect_false: bool = Mapping::contains(balances, account);
19          assert(!expect_false);
20      }
21  }