title: Programmatic default value for Sequelize model
body: <p>How can I create a default value that is generated programmatically upon creation of a new instance of a Sequelize model?  I've read how to do this somewhere, but can't find it anywhere.  I thought this had something to do with <code>classMethods</code>, but I can't figure out what that method should be called.</p>
  
  <p>For example:</p>
  
  <pre><code>sequelize.define('Account', {
    name: DataTypes.STRING
  }, {
    classMethods: {
      something: function (instance) {
        instance.name = 'account12345';
      }
    }
  });
  
  models.account.create(function (account) {
    console.log(account.name); // Echos "account12345" or whatever I
  });
  </code></pre>
  
  <p>If you could point me in the right direction, it would be greatly appreciated.</p>