code: @DELETE
      @Path("/guid/{guid}/classification/{classificationName}")
      @Produces(Servlets.JSON_MEDIA_TYPE)
      public void deleteClassification(@PathParam("guid") String guid,
                                       @PathParam("classificationName") final String classificationName) throws AtlasBaseException {
          AtlasPerfTracer perf = null;
  
          try {
              if (AtlasPerfTracer.isPerfTraceEnabled(PERF_LOG)) {
                  perf = AtlasPerfTracer.getPerfTracer(PERF_LOG, "EntityREST.deleteClassification(" + guid + "," + classificationName + ")");
              }
  
              if (StringUtils.isEmpty(guid)) {
                  throw new AtlasBaseException(AtlasErrorCode.INSTANCE_GUID_NOT_FOUND, guid);
              }
  
              ensureClassificationType(classificationName);
  
              entitiesStore.deleteClassifications(guid, new ArrayList<String>() {{ add(classificationName);}} );
          } finally {
              AtlasPerfTracer.log(perf);
          }
      }
docs: Deletes a given classification from an existing entity represented by a guid.
  @param guid      globally unique identifier for the entity
  @param classificationName name of the classifcation