package DataTable;
use Moose;

has 'tablename' => (is => 'rw', isa => 'Str', required => 1);
has 'columns'   => (
    traits  => [ 'Array'],
    is      => 'rw', 
    isa     => 'ArrayRef[Str]', 
    default => sub { [] },
    handles => {
        'add_column'           => 'push',
        'remove_column_at_idx' => 'delete',
        # ... and many more 
    }
);

# rest of the class snipped off for brevity ...