public override void InvokeEnd(MouseEvent ev)
        {
            base.InvokeEnd(ev);

            if (clicked)
            {
                // HERZUM SPRINT 2.0 TLAB-99
                // Experiment ownerExperiment = m_ownerConnection.Owner;
                IEditableExperiment ownerExperiment = m_ownerConnection.ExperimentNodeConnection.Target.Owner as IEditableExperiment;
                if (ownerExperiment != null)
                {
                    // END HERZUM SPRINT 2.0 TLAB-99
                    ownerExperiment.RemoveConnection(m_ownerConnection.ExperimentNodeConnection);
                }
            }

            clicked = false;
        }
 /// <summary>
 /// Removes the given connection from the m_experiment.
 /// </summary>
 /// <param name="edge">The edge to remove</param>
 /// <exception cref="System.InvalidOperationException">Thrown if the ViewModel is in a bad state that it cannot recover from</exception>
 public void RemoveConnection(ExperimentNodeConnection edge)
 {
     m_experiment.RemoveConnection(edge);
 }