code: public void checkParameters()
          throws ExecutionException
      {
          if ( isFailIfNoFiles() && ( files == null || files.isEmpty() ) )
          {
              throw new ExecutionException( "No file to process." );
          }
          if ( isFailIfNoAlgorithms() && ( algorithms == null || algorithms.isEmpty() ) )
          {
              throw new ExecutionException( "No checksum algorithm defined." );
          }
          if ( isFailIfNoTargets() && ( targets == null || targets.isEmpty() ) )
          {
              throw new ExecutionException( "No output target defined." );
          }
      }
docs: {@inheritDoc}