how to pass List data type to the graphql

I watch the video on youtube and I have a question of pass special data type. for example, if there are two entities class inside the model, one is for Book like yours and another one is author. In the Book entity class,  `private` List `<author>` authors. And in the author class, it contains: authorName, authorAge.... In this case, how should pass authors list into the graphql script?
