Enum in swagger

In case of swagger-maven-plugin 3.1.0 this might be a minimal documentation:

@ApiModel
public class Input {
    @ApiModelProperty
    public Day day;
}

@ApiModel
public enum Day {
    Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday;
}

Then this is the generated json model:

"definitions" : {
  "Input" : {
    "type" : "object",
    "properties" : {
      "day" : {
        "type" : "string",
        "enum" : [ "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday" ]
      }
    }
  }
}

And this is how the model is presented in the SwaggerUI:

Input {
day (string, optional) = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
}