private void AssignWorkoutDefinitionExecute()
        {
            var session = SelectedSessionDefinition;

            var assignment = new WorkOutAssignment
            {
                WorkOutDefinition   = SelectedWorkoutDefinition,
                SessionDefinition   = SelectedSessionDefinition,
                SessionDefinitionId = session.SessionDefinitonId,
                WorkOutDefinitionId = SelectedWorkoutDefinition.WorkOutId,
                WorkoutType         = WorkOutType
            };

            _workOutAssignmentRepository.AssignWorkOutDefinition(assignment);

            session.WorkOutDefinitions.Add(assignment);

            _userInterfaceState.ChangeUserInterfaceState(UserInterfaceStates.SessionDefinitionView);
        }