code: private void initEntityClass() {
          if (from == null) {
              throw new JPQLParseException("Bad query format FROM clause is mandatory for SELECT queries");
          }
          String fromArray[] = from.split(" ");
  
          if (!this.isDeleteUpdate) {
              if (fromArray.length == 3 && fromArray[1].equalsIgnoreCase("as")) {
                  fromArray = new String[] { fromArray[0], fromArray[2] };
              }
  
              if (fromArray.length != 2) {
                  throw new JPQLParseException("Bad query format: " + from
                      + ". Identification variable is mandatory in FROM clause for SELECT queries");
              }
  
              // TODO
              StringTokenizer tokenizer = new StringTokenizer(result[0], ",");
              while (tokenizer.hasMoreTokens()) {
                  String token = tokenizer.nextToken();
                  if (!StringUtils.containsAny(fromArray[1] + ".", token)) {
                      throw new QueryHandlerException("bad query format with invalid alias:" + token);
                  }
              }
          }
  
          this.entityName = fromArray[0];
          if (fromArray.length == 2)
              this.entityAlias = fromArray[1];
  
          persistenceUnit = kunderaMetadata.getApplicationMetadata().getMappedPersistenceUnit(entityName);
  
          // Get specific metamodel.
          MetamodelImpl model = getMetamodel(persistenceUnit);
  
          if (model != null) {
              entityClass = model.getEntityClass(entityName);
          }
  
          if (null == entityClass) {
              logger.error(
                  "No entity {} found, please verify it is properly annotated with @Entity and not a mapped Super class",
                  entityName);
              throw new QueryHandlerException("No entity found by the name: " + entityName);
          }
  
          EntityMetadata metadata = model.getEntityMetadata(entityClass);
  
          if (metadata != null && !metadata.isIndexable()) {
              throw new QueryHandlerException(entityClass + " is not indexed. Not possible to run a query on it."
                  + " Check whether it was properly annotated for indexing.");
          }
      }
docs: Inits the entity class.