docs: def get(self):
          """
          Get a JSON-ready representation of this Personalization.
  
          :returns: This Personalization, ready for use in a request body.
          :rtype: dict
          """
          personalization = {}
  
          for key in ['tos', 'ccs', 'bccs']:
              value = getattr(self, key)
              if value:
                  personalization[key[:-1]] = value
  
          for key in ['subject', 'send_at', 'dynamic_template_data']:
              value = getattr(self, key)
              if value:
                  personalization[key] = value
  
          for prop_name in ['headers', 'substitutions', 'custom_args']:
              prop = getattr(self, prop_name)
              if prop:
                  obj = {}
                  for key in prop:
                      obj.update(key)
                      personalization[prop_name] = obj
  
          return personalization