Damages and losses don't return the same number of rows (link based)

[ArdtK]

Ra2ce version checks

• I have checked that this issue has not already been reported.
• I have checked that this bug exists on the latest version of Ra2ce in master here.

Reproducible example

Run example_adaptation.
Damages: 230 rows
Losses 228 rows

Current behaviour

These lines are missing in the losses output

Desired behaviour

The same amount of lines (with matching IDs) should be returned, identical to the IDs of the input (simplified graph used in losses)

Additional context

No response

[ArdtK]

These statement in losses_base.py cause the 2 rows to get lost:

        if "key" in criticality_analysis.columns:
            criticality_analysis = criticality_analysis.drop_duplicates(
                ["u", "v", "key"]
            )
        else:
            criticality_analysis = criticality_analysis.drop_duplicates(["u", "v"])

This is because some rows have identical u,v(,key).

[ArdtK]

@sahand-asgarpour could you indicate what the right behavior would be?

• Should it be possible to have 2 links between the same nodes?
• What should be done when calling drop_duplicates?