new-contract.java

public class MyContract extends StandardContract implements Contract {
  
    public interface Commands extends CommandData {
      
        // note the annotations here from the Contracts SDK
        @RequireNumberOfStatesOnInput(value = 0)
        @RequireNumberOfStatesOnOutput(value = 1)
        class Action implements Commands {}
      
        // now the verification is clearer, and easier to read
        @RequireNumberOfStatesOnInput(value = 0)
        class SomeOtherAction implements Commands {}
    }
  
}