code: @Override
      public <Y> Expression<Y> coalesce(Expression<? extends Y> arg0, Y arg1)
      {
          // TODO Auto-generated method stub
          return null;
      }
docs: /*
  (non-Javadoc)
  
  @see
  javax.persistence.criteria.CriteriaBuilder#coalesce(javax.persistence
  .criteria.Expression, java.lang.Object)