code: @PostMapping(value = "/{entityTypeId}", params = "_method=GET", produces = APPLICATION_JSON_VALUE)
    public EntityCollectionResponse retrieveEntityCollectionPost(
        @PathVariable("entityTypeId") String entityTypeId,
        @Valid @RequestBody EntityCollectionRequest request) {
      Set<String> attributesSet = toAttributeSet(request.getAttributes());
      Map<String, Set<String>> attributeExpandSet = toExpandMap(request.getExpand());
  
      return retrieveEntityCollectionInternal(
          entityTypeId, request, attributesSet, attributeExpandSet);
    }
docs: Same as retrieveEntityCollection (GET) only tunneled through POST.
  
  <p>Example url: /api/v1/person?_method=GET
  
  <p>Returns json