With this method we would test it by creating a couple of tokens. Something like:

```ruby
describe 'before_create' do
  it 'deletes previous matching tokens' do
    user = Factory.create(:user)
    token1 = Token.create!({:user => user, :action => 'blargh'})
    token2 = Token.create!({:user => user, :action => 'blargh'})
    expect {
      token1.reload
    }.to raise_error(ActiveRecord::RecordNotFound
  end
end
```