library method that calls Mojo::Promise->map()

map.pl

return Mojo::Promise->map                   
(                                           
   { concurrency => 10 },                   
   sub
   {
      my $record  = $_;
      my $promise = Mojo::Promise->new(); 
      
      Mojo::IOLoop->subprocess->run
      (
         sub { $self->do_work_and_warn_about_progress_to_STDERR( $record ) },
         sub
         {
            my ( $subprocess, $err, $result ) = @_;
            
            if ( $err )
            {
               $promise->reject( $err )
            }
            else
            {
               $promise->resolve( $result );
            }
         }
      );
      
      return $promise;
   },
   @records                                  
);