Hossein Sadeghi

oh, that raises very good questions. I had not thought about it. For now, I think it should just raise an error.

This could either use a function or operator overloading of `__add__` and `__radd__` `new_bqm = sum(bqms)`

I have been thinking about this. I believe that the operations (+, -, *, pow(), sum()) should always return a new object. For example: `bqm + bqm + bqm` can...

nope. I had the wrong starting point in my head. To save space, one might consider modifying the largest BQM rather than creating a new one.

In 0.10.x there are two BQM objects, AdjVectorBQM and AdjDictBQM. right? Should all methods add to both objects as well as DQM? All in one PR or multiple PR?

The case value of a variable is a property of the `SampleSet`. It may be interesting to be able to change variable case in a sampleset and observe the modified...

okay, I guess I didn't understand what you meant by negating cases. Would `dqm.fix_variable_case('a', 4, 0)` remove case 4? and therefore reduce the dqm.num_cases('a') by one? If so, this would...