def __init__(self, user_name = None, user_password=None, session = None):
'''
This constructor has at least a session object to start petitions agains
'''
if session != None:
self.session = session
elif user_name != None and user_password != None:
self.session = Models.get_session(user_name, user_password, sqlite=False)
else:
self.session = Models.get_session()
