docs: @Override
     public void registerPersisterSpace(String entityName, Tree aliasTree) {
        String aliasText = aliasTree.getText();
        String previous = aliasToEntityType.put(aliasText, entityName);
        if (previous != null && !previous.equalsIgnoreCase(entityName)) {
           throw new UnsupportedOperationException("Alias reuse currently not supported: alias " + aliasText + " already assigned to type " + previous);
        }
        if (targetTypeName != null) {
           throw new IllegalStateException("Can't target multiple types: " + targetTypeName + " already selected before " + entityName);
        }
        targetTypeName = entityName;
        targetEntityMetadata = propertyHelper.getEntityMetadata(targetTypeName);
        if (targetEntityMetadata == null) {
           throw log.getUnknownEntity(targetTypeName);
        }
        fieldIndexingMetadata = propertyHelper.getIndexedFieldProvider().get(targetEntityMetadata);
        whereBuilder.setEntityType(targetEntityMetadata);
        havingBuilder.setEntityType(targetEntityMetadata);
     }