The weights of ClientsAndWeights aren't guaranteed to be sorted for binary searching

[futurely]

RandomWeightedLoadBalancer selects the client using Collections.binarySearch which requires the list to be sorted to avoid undefined results. There are no preconditions to check that the weights are actually sorted.

[elandau]

The list is assumed to be sorted. I'll add documentation to call that out but I don't see the value of doing an actual precondition check.