code: def get_auth_bearer(self):
          
          access_token = ''
          auth_header = self.get_header('authorization')
          if auth_header:
              m = re.search(r"^Bearer\s+(\S+)$", auth_header, re.I)
              if m: access_token = m.group(1)
  
          return access_token
docs: return the bearer token in the authorization header if it exists