':param credentials:
:param contacts: list of [jid ]
:param encryptionEnabled:
:return:'

def __init__(self, credentials, contacts, encryptionEnabled=False):

    stackBuilder = YowStackBuilder()
    self.stack = stackBuilder.pushDefaultLayers(encryptionEnabled).push(SyncLayer).build()
    self.stack.setProp(SyncLayer.PROP_CONTACTS, contacts)
    self.stack.setProp(YowAuthenticationProtocolLayer.PROP_PASSIVE, True)
    self.stack.setCredentials(credentials)
