docs: def get_image(self, filename: str=None) -> None:
          """Download the photo associated with a Savings Goal."""
          if filename is None:
              filename = "{0}.png".format(self.name)
  
          endpoint = "/account/{0}/savings-goals/{1}/photo".format(
              self._account_uid,
              self.uid
          )
  
          response = get(
              _url(endpoint, self._sandbox),
              headers=self._auth_headers
          )
          response.raise_for_status()
  
          base64_image = response.json()['base64EncodedPhoto']
          with open(filename, 'wb') as file:
              file.write(b64decode(base64_image))