数据加载问题

哈喽，我已经通过gl.Graph().node()......edge().......init()的形式定义好了整个的图结构，但是我们有三种类型的节点存在一个csv文件里，记作三元组（a, b, c），现在我们想加载这个文件，每次读取一个batch分别并进行采样得到a, b, c的EgoGraph有什么好的方法可以实现嘛

Start from the gl.Graph().node(), edge(), and init() entry points mentioned in the issue, then locate how CSV graph data and EgoGraph sampling are currently handled. Determine whether the requested batch loading and three-node-type sampling behavior is supported; done means the project has a documented or implemented path for reading each batch and producing the corresponding EgoGraphs.

Written by the indexing model from the issue text.