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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 unshare_project(project_id, usernames,**kwargs):
 """ Un-share a project with a list of users, identified by their usernames. """


    user_id = kwargs.get('user_id')
    proj_i = _get_project(project_id)
    proj_i.check_share_permission(user_id)

    for username in usernames:
        user_i = _get_user(username)
        #Set the owner ship on the network itself
        proj_i.unset_owner(user_i.id, write=write, share=share)
    db.DBSession.flush()