Arrays in models don't render

[stuartf]

I have a model like:

@ApiModel({
    description: "A Course",
    name: "Course",
})
export class CourseModel {
    @ApiModelProperty({
        required: true,
    })
    id!: number;
    @ApiModelProperty({
        required: true,
    })
    students: Array<Student>;
}

And the rendered swagger.json comes out with:

...
"Course":{
    "type":"object",
    "properties":{
        "id":{"type":"number"},
        "students":{"type":"array"}
    },
    "required":["id","students"],
    "description":"A Course"
}
...

It would seem that Course.properties.students is missing an element items that should contain a reference to the Student model.