define custom `dgraphType` result in unexpected schema

[joeslee]

schema define:

@Node({
  dgraphType: 'Post'
})
export class PostEntity {
  @Property({
    type: PropertyType.String
  })
  title: string;
}

schema build output:

type Post {
  PostEntity.title: string // prefix is classname and type restrict  is unnecessary.
}
PostEntity.title: string .

expect output:

type Post {
  Post.title
}
Post.title: string .

It works well, but the result is not expected.