resolve open issues for newpss

[mortelli]

#2150 was merged, but there are still a few issues to be resolved:

• [x] what will happen if we retrieve 2 different chunks with the same addr field?
• [ ] how should we compare 2 chunks? see here and here
• [x] what should be the correct return type of Send?

[mortelli]

what will happen if we retrieve 2 different chunks with the same addr field?

this was a very silly question on my part. chunks are not sent to an address, but rather distributed organically based on their data, which naturally results in an address.

apologies to @santicomp2014 who tried to point this out in the original thread.

[mortelli]

what should be the correct return type of Send?

this question no longer applies as #2159 has updated the signature for this function.