@RequestMapping(value = "variants", method = RequestMethod.POST)
 @ResponseBody
 public List<Variant> getVariants(@RequestBody BrowseRequest request) throws IOException {
   return vcfManager.readVcf(request);
 }
 @RequestMapping(value = "reference", method = RequestMethod.GET)
 @ResponseBody
 public String getReference() throws IOException {
   return vcfManager.readReference();
 }