Fix Error Combining Composite Token-Token Params

[juliangruendner]

When a composite search parameter of type token-token (such as the standard code-value-concept and combo-code-value-concept, or the custom MII mii-provision-provision-code-type) is combined with another, more selective search parameter, the request fails with an AbstractMethodError.

The composite parameter is only affected when the query planner evaluates it as a secondary (seek) clause — i.e. when it is combined with a more selective clause. On its own, or as the leading (scan) clause, it works.

Reproduction

GET /fhir/Consent?category=2.16.840.1.113883.3.1937.777.24.2.184&mii-provision-provision-code-type=urn:oid:2.16.840.1.113883.3.1937.777.24.5.3|2.16.840.1.113883.3.1937.777.24.5.3.7$permit

returns:

{
  "resourceType": "OperationOutcome",
  "issue": [
    {
      "severity": "error",
      "code": "exception",
      "diagnostics": "Method blaze/db/impl/search_param/composite/token_token/SearchParamCompositeTokenToken._single_version_id_matcher(Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object; is abstract"
    }
  ]
}

The same error occurs with the standard code-value-concept parameter on Observation, for example Observation?patient=<id>&code-value-concept=<code>$<value> where the patient clause is more selective than the code-value-concept clause.

Cause

SearchParamCompositeTokenToken does not implement the -single-version-id-matcher method of the SearchParam protocol. That method is invoked whenever the parameter is filtered as a seek clause, so calling it on the unimplemented record raises the AbstractMethodError. The sibling SearchParamCompositeTokenQuantity (used by code-value-quantity) implements it, which is why token-quantity composites are unaffected.

Expected

The combined query returns the matching resources without error.