Is the testimony of a witness who confirms the claim of the one denying the liability (the claimant's opponent) accepted?

Primary text

The testimony of a just witness (adl) who testifies in favor of the denier is accepted, provided that this testimony does not draw a benefit to themselves or ward off harm from themselves. This witness must swear an oath alongside their testimony. If the witness is not just (not adl), their testimony is considered void, as if it never occurred.