Mutations

type Mutation {

sellBook(
   course: String!,
   location: String!,
   title: String!,
   author: String!,
   ISBN: String!,
   edition: String!,
   grade: [AllowedGrades],
   price: Float!,
   donation: Boolean,
   coverImage: String!,
   spineImage: String!,
   forEdgeImage: String!,
   seller: String!,
   datePosted: String!,
   dateSold: String,
   sold: Boolean
    ): Book  
   

}