fix #404

[chicco785]

Proposed changes

see #404

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing
  functionality to not work as expected)

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Further comments

separated default_backend computation logic for easy reusage

[github-actions]

CLA Assistant Lite bot All contributors have signed the CLA ✍️

[c0c0n3]

good stuff!!