In the fireREST.fmc.devicehapair constructor the method is named "ftdhapair" while in the directory tree and docs is named "ftddevicehapair".
from fireREST.fmc import Connection
from fireREST.fmc.devicehapair.ftddevicehapair import FtdHAPair
class DeviceHAPair:
def init(self, conn: Connection):
self.ftdhapair = FtdHAPair(conn)