code: @GET
      @Path("/dsl")
      @Consumes(Servlets.JSON_MEDIA_TYPE)
      @Produces(Servlets.JSON_MEDIA_TYPE)
      public AtlasSearchResult searchUsingDSL(@QueryParam("query")          String query,
                                              @QueryParam("typeName")       String typeName,
                                              @QueryParam("classification") String classification,
                                              @QueryParam("limit")          int    limit,
                                              @QueryParam("offset")         int    offset) throws AtlasBaseException {
          AtlasPerfTracer perf = null;
  
          try {
              if (AtlasPerfTracer.isPerfTraceEnabled(PERF_LOG)) {
                  perf = AtlasPerfTracer.getPerfTracer(PERF_LOG, "DiscoveryREST.searchUsingDSL(" + query + "," + typeName
                                                              +  "," + classification + "," + limit + "," + offset + ")");
              }
  
              String queryStr = query == null ? "" : query;
  
              if (StringUtils.isNoneEmpty(typeName)) {
                  queryStr = escapeTypeName(typeName) + " " + queryStr;
              }
  
              if (StringUtils.isNoneEmpty(classification)) {
                  // isa works with a type name only - like hive_column isa PII; it doesn't work with more complex query
                  if (StringUtils.isEmpty(query)) {
                      queryStr += (" isa " + classification);
                  }
              }
  
              return atlasDiscoveryService.searchUsingDslQuery(queryStr, limit, offset);
          } finally {
              AtlasPerfTracer.log(perf);
          }
      }
docs: Retrieve data for the specified DSL
  @param query DSL query
  @param typeName limit the result to only entities of specified type or its sub-types
  @param classification limit the result to only entities tagged with the given classification or or its sub-types
  @param limit limit the result set to only include the specified number of entries
  @param offset start offset of the result set (useful for pagination)
  @return Search results
  @throws AtlasBaseException
  @HTTP 200 On successful DSL execution with some results, might return an empty list if execution succeeded
  without any results
  @HTTP 400 Invalid DSL or query parameters