independentFailures

For Multiplicity.MULTIPLE_POINT failures: the independent failure(s) that, in combination with this failure, can violate the safety goal. At least one entry is required when multiplicity is MULTIPLE_POINT and severity is at or above S10 or missing. A severity explicitly below S10 exempts this reference requirement, regardless of ASIL; a failure can list more than one independent alternative (e.g. several distinct failure modes that each independently combine with this one to violate the safety goal). Each alternative must belong to a different element on a separate hierarchy branch: neither element may be an ancestor of the other. A valid alternative also satisfies the S10 mitigation requirement.

Declared var for the same back-patch reason as mitigatedBy/propagatesTo: the PSI source-materializer (:stig-idea-plugin) resolves list-of-reference arguments after all entities exist in the scope (handles cycles between failures). Compiled-path callers should treat this as effectively immutable — set once via the constructor.