declare module "checkstyle-formatter" {
  declare type CheckstyleMessage = {
    line: number,
    column: number,
    severity: "error" | "warning",
    message: string
  };

  declare type CheckstyleFileResult = {
    filename: string,
    messages: Array<CheckstyleMessage>
  };

  declare type CheckstyleResult = Array<CheckstyleFileResult>;

  declare module.exports: (result: CheckstyleResult) => string;
}
