code: private void fillPrimaryKeysBySequence(Object entity){
          if(!dialect.supportsGenerationType(GenerationType.SEQUENCE)){
              return;
          }
  
          BeanDesc beanDesc = beanDescFactory.getBeanDesc(entity.getClass());
          int size = beanDesc.getPropertyDescSize();
  
          for(int i=0; i < size; i++){
              PropertyDesc propertyDesc = beanDesc.getPropertyDesc(i);
              PrimaryKey primaryKey = propertyDesc.getAnnotation(PrimaryKey.class);
  
              if(primaryKey != null && primaryKey.generationType() == GenerationType.SEQUENCE){
                  String sql = dialect.getSequenceSql(primaryKey.generator());
                  Object value = sqlExecutor.getSingleResult(propertyDesc.getPropertyType(), sql, new Object[0]);
                  propertyDesc.setValue(entity, value);
              }
          }
      }
docs: Sets GenerationType.SEQUENCE properties value.