title: Delete association in hasMany relation
body: <p>I'm new in Grails and have a problem with the hasMany relation. I've got the following classes:</p>
  
  <pre><code>class Twitter{
      String someVariable
      static hasMany = [subscribedUsers: User]
  }
  
  class User {
      String username
      String anotherVariable
  }
  </code></pre>
  
  <p>In my Code beforde, I added a User to the relationship via</p>
  
  <pre><code>twitterInstance.addToSubscribedUsers(springSecurityService.currentUser)
  </code></pre>
  
  <p>which worked fine. But now, I am trying to delete a User from the relationship without deleting the User object. I've read some tutorials and the GORM doc, but couldn't find something like</p>
  
  <pre><code>twitterInstance.removeFromSubscribedUsers(springSecurityService.currentUser)
  </code></pre>
  
  <p>Can anyone help me?</p>