Column Width!

How do you set the width for a column? Am I missing something? How are people adjusting column sizes?

It would be great if it was a simple as => 
`   var columns = [ 
     {
      title: 'FirstName',
      field: 'firstName',
      width: 100
    },
    {
      title: 'LastName',
      field: 'lastName',
      width: 100
    }
    ];`