old_contents: import requests
  import os
  from .endpoints import *
  
  
  class UnauthorizedToken(Exception):
      pass
  
  
  class ReviewsAPI:
  
      def __init__(self):
          token = os.environ['UDACITY_AUTH_TOKEN']
          self.headers = {'Authorization': token, 'Content-Length': '0'}
  
      def execute(self, request):
          try:
              raw_response = request()
              response = raw_response.json()
  
              raw_response.raise_for_status()
  
              return response
          except requests.exceptions.HTTPError:
              raise UnauthorizedToken('Maybe it\'s time to change your token!')
  
      def certifications(self):
          return self.execute(lambda : requests.get(CERTIFICATIONS_URL, headers=self.headers))
  
      def certified_languages(self):
          response = self.execute(lambda : requests.get(REVIEWER_URL, headers=self.headers))
          return [language for language in response['application']['languages']]
  
      def request_reviews(self, projects):
          return self.execute(lambda : requests.post(SUBMISSION_REQUESTS_URL, json=projects, headers=self.headers))
  
new_contents: import requests
  import os
  from .endpoints import *
  
  
  class UnauthorizedToken(Exception):
      pass
  
  
  class ReviewsAPI:
  
      def __init__(self):
          token = os.environ['UDACITY_AUTH_TOKEN']
          self.headers = {'Authorization': token, 'Content-Length': '0'}
  
      def execute(self, request):
          try:
              raw_response = request()
              response = raw_response.json()
  
              raw_response.raise_for_status()
  
              return response
          except requests.exceptions.HTTPError:
              raise UnauthorizedToken('Maybe it\'s time to change your token!')
  
      def certifications(self):
          return self.execute(lambda:requests.get(CERTIFICATIONS_URL, headers=self.headers))
  
      def certified_languages(self):
          response = self.execute(lambda:requests.get(REVIEWER_URL, headers=self.headers))
          return [language for language in response['application']['languages']]
  
      def request_reviews(self, projects):
          return self.execute(lambda:requests.post(SUBMISSION_REQUESTS_URL, json=projects, headers=self.headers))
  
subject: Remove whitespaces from lambda expression