Mystery plant No.5?

I noticed this plant on a property in Dudley, NSW.

I asked about it on facebook NSW plant identification group:

It looks similar to Senna, and there is Senna in the area, but these leaves were much bigger and did not have the usual yellow margin that Senna has. I notice the leaflets are mostly opposite but not all of them. This plant was about a metre in height.

Most likely suggestion was: Robinia pseudoacacia

It seems to match images:

and the description:

But I still need to return to confirm some of the characteristics (ie alternative leaf structure, spines near base of leaves).