old_contents: from werkzeug.exceptions import HTTPException
  import json
  
  class ExceptionFieldNotFound(HTTPException):
      def __init__(self, required_fields, all_required_fields, all_fields):
          self.response = None
          _required_field = ', '.join(required_fields)
          _all_required_fields = ', '.join(all_required_fields)
          _all_fields = ', '.join(all_fields)
          self.description = 'Field "%s" not found, you must pass "%s", you can pass "%s"' % (
              _required_field,
              _all_required_fields,
              _all_fields
          )
  
      def get_body(self, environ=None):
          return json.dumps(dict(error=self.description))
  
      def get_headers(self, environ=None):
          return [('Content-Type', 'application/json')]
  
  
new_contents: from werkzeug.exceptions import HTTPException
  import json
  
  class ExceptionFieldNotFound(HTTPException):
      def __init__(self, required_fields, all_required_fields, all_fields):
          self.response = None
          _required_field = ', '.join(required_fields)
          _all_required_fields = ', '.join(all_required_fields)
          _all_fields = ', '.join(all_fields)
          self.description = 'Field "%s" not found, you must pass "%s", you can pass "%s"' % (
              _required_field,
              _all_required_fields,
              _all_fields
          )
  
      def get_body(self, environ=None):
          return json.dumps(dict(error=self.description))
  
      def get_headers(self, environ=None):
          return [('Content-Type', 'application/json')]
  
  class ExceptionFieldValidation(ExceptionFieldNotFound):
      def __init__(self, field, description=None):
          self.response = None
          self.description = 'Invalid data type for field "%s"' % field
          if description:
              self.description += ', "%s"' % description
subject: Make exceptions cls