old_contents: import flask
  from flask import request
  import functools
  
  from etiquette import jsonify
  
  
  def required_fields(fields, forbid_whitespace=False):
      '''
      Declare that the endpoint requires certain POST body fields. Without them,
      we respond with 400 and a message.
  
      forbid_whitespace:
          If True, then providing the field is not good enough. It must also
          contain at least some non-whitespace characters.
      '''
      def wrapper(function):
          @functools.wraps(function)
          def wrapped(*args, **kwargs):
              for requirement in fields:
                  missing = (
                      requirement not in request.form or
                      (forbid_whitespace and request.form[requirement].strip() == '')
                  )
                  if missing:
                      response = {
                          'error_type': 'MISSING_FIELDS',
                          'error_message': 'Required fields: %s' % ', '.join(fields),
                      }
                      response = jsonify.make_json_response(response, status=400)
                      return response
  
              return function(*args, **kwargs)
          return wrapped
      return wrapper
  
new_contents: import flask
  from flask import request
  import functools
  
  from . import jsonify
  
  
  def required_fields(fields, forbid_whitespace=False):
      '''
      Declare that the endpoint requires certain POST body fields. Without them,
      we respond with 400 and a message.
  
      forbid_whitespace:
          If True, then providing the field is not good enough. It must also
          contain at least some non-whitespace characters.
      '''
      def wrapper(function):
          @functools.wraps(function)
          def wrapped(*args, **kwargs):
              for requirement in fields:
                  missing = (
                      requirement not in request.form or
                      (forbid_whitespace and request.form[requirement].strip() == '')
                  )
                  if missing:
                      response = {
                          'error_type': 'MISSING_FIELDS',
                          'error_message': 'Required fields: %s' % ', '.join(fields),
                      }
                      response = jsonify.make_json_response(response, status=400)
                      return response
  
              return function(*args, **kwargs)
          return wrapped
      return wrapper
  
subject: Fix required_fields looking at wrong jsonify file.