This is a completely different species, but I have placed it here for convenience. As this bean sometimes appears in the seed catalogues, it is appropriate to give some basic information about it.
The lab lab bean probably originated in South East Asia, and is mainly cultivated in the tropics and the sub-tropics. It is an important food crop in these areas. It is an annual or short lived perennial vine and grows to some 3 m in height. It has violet to white flowers with green foliage and eventually has green pods about 5 cm long.
It needs a well drained soil in full sun and a lot of heat to flower and produce the pods. Even when grown in a cool greenhouse in Glasgow, there was a very small crop produced.
The young pods are cooked as you would cook other peas and beans. If the mature seeds are saved for eating, remember that as the seeds contain toxins, the seeds need to be thoroughly cooked before eating them.
Remembering that it requires warm to hot conditions, such as you would find in the tropics, it is not really suitable for the climate in the North of the UK. I would not grow it again.