code: @PostMapping(
        value = "/{entityTypeId}/meta",
        params = "_method=GET",
        produces = APPLICATION_JSON_VALUE)
    public EntityTypeResponse retrieveEntityTypePost(
        @PathVariable("entityTypeId") String entityTypeId,
        @Valid @RequestBody EntityTypeRequest request) {
      Set<String> attributesSet = toAttributeSet(request != null ? request.getAttributes() : null);
      Map<String, Set<String>> attributeExpandSet =
          toExpandMap(request != null ? request.getExpand() : null);
  
      EntityType meta = dataService.getEntityType(entityTypeId);
      return new EntityTypeResponse(
          meta, attributesSet, attributeExpandSet, permissionService, dataService);
    }
docs: Same as retrieveEntityType (GET) only tunneled through POST.
  
  <p>Example url: /api/v1/person/meta?_method=GET
  
  @return EntityType