pathway count for PubMed reference does not have a useful _about

[egonw]

When I ask for the number of pathways for some PubMed identifier (e.g. https://beta.openphacts.org/2.2/pathways/byReference/count?uri=http%3A%2F%2Fidentifiers.org%2Fpubmed%2F14769483&app_id=91f5d4d0&app_key=1af5086da757e57c553bfa1351708d5f) then the results has an _about for the primary topic from which I cannot recover the PubMed identifier. This causes problems if I want to link the count back to the identifier. This is the resulting JSON for the above query:

{
  "format": "linked-data-api",
  "version": "2.2",
  "result": {
    "_about": "http://beta.openphacts.org:3002/2.2/pathways/byReference/count?uri=http%3A%2F%2Fidentifiers.org%2Fpubmed%2F14769483&app_id=91f5d4d0&app_key=1af5086da757e57c553bfa1351708d5f",
    "definition": "http://beta.openphacts.org:3002/api-config",
    "extendedMetadataVersion": "http://beta.openphacts.org:3002/2.2/pathways/byReference/count?uri=http%3A%2F%2Fidentifiers.org%2Fpubmed%2F14769483&app_id=91f5d4d0&app_key=1af5086da757e57c553bfa1351708d5f&_metadata=all%2Cviews%2Cformats%2Cexecution%2Cbindings%2Csite",
    "linkPredicate": "http://www.w3.org/2004/02/skos/core#exactMatch",
    "activeLens": "Default",
    "primaryTopic": {
      "_about": "http://www.wikipathways.org",
      "pathway_count": 9,
      "isPrimaryTopicOf": "http://beta.openphacts.org:3002/2.2/pathways/byReference/count?uri=http%3A%2F%2Fidentifiers.org%2Fpubmed%2F14769483&app_id=91f5d4d0&app_key=1af5086da757e57c553bfa1351708d5f"
    }
  }
}