New Features
- Add `close()` to all QPU and hybrid samplers. See [\77](https://github.com/dwavesystems/dwave-system/issues/77), [\#554](https://github.com/dwavesystems/dwave-system/pull/554).
- Add support for context manager protocol to all samplers. See [\91](https://github.com/dwavesystems/dwave-system/issues/91), [\#556](https://github.com/dwavesystems/dwave-system/pull/556).
The recommended way to use [DWaveSampler](https://docs.ocean.dwavesys.com/en/latest/docs_system/reference/samplers.html#dwave.system.samplers.DWaveSampler) is now from a [runtime context](https://docs.python.org/3/reference/datamodel.html#with-statement-context-managers):
python
with DWaveSampler() as sampler:
sampler.sample_ising(...)
Alternatively, call the [close()](https://docs.ocean.dwavesys.com/en/latest/docs_system/reference/generated/dwave.system.samplers.DWaveSampler.close.html#dwave.system.samplers.DWaveSampler.close) method to terminate the sampler resources:
sampler = DWaveSampler()
...
sampler.close()