The pods of course will probably contain a row of seeds (like all members of the pea family). When they are fully ripe (starting to turn brown and split), you can sow the seed. I must point out that Wisteria on it's own roots is slow to flower in most cases and you may have to wait at least ten years or more. A mere slip in time to this plant as it is incredibly long lived, perhaps 2-3 hundred years (examples in China). I'm sure I have read somewhere of a specimen estimated to be considerably older in China?