code: function Role(roleName, validationFunction) {
      validateConstructor(roleName, validationFunction);
  
      this.roleName = roleName;
      this.validationFunction = annotateValidationFunction(validationFunction);
    }
docs: Role definition constructor
  @constructor Role
  
  @param roleName {String} Name representing role
  @param validationFunction {Function|Array<String>} Optional function used to validate if permissions are still
  valid or list of permission names representing role