old_contents: from flask import Blueprint, jsonify
  
  errors_bp = Blueprint('errors', __name__)
  
  
  class Error(Exception):
      def __init__(self, message, status_code=None):
          Exception.__init__(self)
          self.message = message
          if status_code is not None:
              self.status_code = status_code
  
      def to_dict(self):
          return {'error': self.message}
  
  
  class BadRequest(Error):
      status_code = 400
  
  
  class Unauthorized(Error):
      status_code = 401
  
  
  class UnprocessableEntity(Error):
      status_code = 422
  
  
  class InternalServerError(Error):
      status_code = 500
  
  
  @errors_bp.app_errorhandler(Error)
  @errors_bp.app_errorhandler(BadRequest)
  @errors_bp.app_errorhandler(InternalServerError)
  @errors_bp.app_errorhandler(Unauthorized)
  def handle_error(error):
      resp = jsonify(error.to_dict())
      resp.status_code = error.status_code
      return resp
  
new_contents: from flask import Blueprint, jsonify
  
  errors_bp = Blueprint('errors', __name__)
  
  
  class Error(Exception):
      def __init__(self, message, status_code=None):
          Exception.__init__(self)
          self.message = message
          if status_code is not None:
              self.status_code = status_code
  
      def to_dict(self):
          return {'error': self.message}
  
  
  class BadRequest(Error):
      status_code = 400
  
  
  class Unauthorized(Error):
      status_code = 401
  
  
  class UnprocessableEntity(Error):
      status_code = 422
  
  
  class InternalServerError(Error):
      status_code = 500
  
  
  @errors_bp.app_errorhandler(Error)
  @errors_bp.app_errorhandler(BadRequest)
  @errors_bp.app_errorhandler(InternalServerError)
  @errors_bp.app_errorhandler(Unauthorized)
  @errors_bp.app_errorhandler(UnprocessableEntity)
  def handle_error(error):
      resp = jsonify(error.to_dict())
      resp.status_code = error.status_code
      return resp
  
subject: Add missing errorhandler