code: @POST
      @Path("/guid/{guid}/classifications")
      @Consumes({Servlets.JSON_MEDIA_TYPE, MediaType.APPLICATION_JSON})
      @Produces(Servlets.JSON_MEDIA_TYPE)
      public void addClassifications(@PathParam("guid") final String guid, List<AtlasClassification> classifications) throws AtlasBaseException {
          AtlasPerfTracer perf = null;
  
          try {
              if (AtlasPerfTracer.isPerfTraceEnabled(PERF_LOG)) {
                  perf = AtlasPerfTracer.getPerfTracer(PERF_LOG, "EntityREST.addClassifications(" + guid + ")");
              }
  
              if (StringUtils.isEmpty(guid)) {
                  throw new AtlasBaseException(AtlasErrorCode.INSTANCE_GUID_NOT_FOUND, guid);
              }
  
              entitiesStore.addClassifications(guid, classifications);
          } finally {
              AtlasPerfTracer.log(perf);
          }
      }
docs: Adds classifications to an existing entity represented by a guid.
  @param guid globally unique identifier for the entity