'@param None|LibNaCLPK public_key: public key object of the hop'

def __init__(self, public_key=None):

    assert ((public_key is None) or isinstance(public_key, LibNaCLPK))
    self.session_keys = None
    self.dh_first_part = None
    self.dh_secret = None
    self.address = None
    self.public_key = public_key
