<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def get_notifications(user):
    '''List notification for a given user'''
    notifications = []

    for name, func in _providers.items():
        notifications.extend([{
            'type': name,
            'created_on': dt,
            'details': details
        } for dt, details in func(user)])

    return notifications