anchor.diff:      buttons: [
         {
           extend: 'copy',
  -        className: 'btn-sm btn-outline-secondary',
           exportOptions: {
             columns: ':visible',
             search: ':applied'
  
positive.code:       },
        { 
          extend: 'print',
          className: 'btn-sm btn-outline-secondary',
        },
        {
          extend: 'colvis',
          className: 'btn-sm btn-outline-secondary',
          text: "<%= I18n.t('lackmus.change_columns') %>",
          columns: ':gt(0)'
        }
  
negative.code:       },
        {
          extend: 'excel',
          exportOptions: {
            columns: ':visible',
            search: ':applied'
  