CQM.add_variables-performance-aed230e912968431.yaml

---
features:
  - Improve the performance of the ``ConstrainedQuadraticModel.add_variables()`` method.
upgrade:
  - Remove the undocumented ``cyConstrainedQuadraticModel.add_variable()`` method.
fixes:
  - |
    Fix ``ConstrainedQuadraticModel.add_variable()`` to raise a ``ValueError``
    when given an inconsistent variable type.
    Previously it incorrectly raised a ``TypeError``.
  - |
    Fix ``ConstrainedQuadraticModel.add_variable()`` to raise a ``ValueError``
    when given invalid variable bounds.