anchor.diff:  ## Count of annotated taxa [/taxon/annotated_taxa_count{?in_taxon}]
   ### Retrieve count of taxa with direct annotations within the given super-taxon [GET]
   + Parameters
  -    + in\_taxon (optional, URI, `http://purl.obolibrary.org/obo/VTO_0034991`) ... A taxon group to limit the results
  +    + `in_taxon` (optional, URI, `http://purl.obolibrary.org/obo/VTO_0034991`) ... A taxon group to limit the results
   + Response 200 (application/json)   
   
           {
  
positive.code:             }, {
              "@id": "http://purl.obolibrary.org/obo/UBERON_0008907"
          }]
          }
  
  # Group OntoTrace
  
negative.code: + Parameters
      + entity (optional, string `<http://purl.obolibrary.org/obo/BFO_0000050> some <http://purl.obolibrary.org/obo/UBERON_0003097>`) ... Anatomical class expression in [OWL Manchester syntax](http://www.w3.org/TR/owl2-manchester-syntax/)
      + quality (optional, string `<http://purl.obolibrary.org/obo/PATO_0000052>`) ... Quality class expression in [OWL Manchester syntax](http://www.w3.org/TR/owl2-manchester-syntax/)
      + `in_taxon` (optional, URI, `http://purl.obolibrary.org/obo/VTO_0034991`) ... A taxon group to limit the results
      + limit (optional, integer `20`)
      + offset (optional, integer, `0`)
      + total (optional, boolean, `false`) ... whether to return the total result count rather than the results
  