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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def delete_resourcegroup(group_id,**kwargs):
 """ Add a new group to a scenario. """

    group_i = _get_group(group_id)
    #This should cascaded to delete all the group items.
    db.DBSession.delete(group_i)
    db.DBSession.flush()

    return 'OK'