docs: def add_bcc(
              self,
              bcc_email,
              global_substitutions=None,
              is_multiple=False,
              p=0):
          """Adds a Bcc object to the Personalization object
  
          :param to_emails: An Bcc object
          :type to_emails: Bcc
          :param global_substitutions: A dict of substitutions for all recipients
          :type global_substitutions: dict
          :param is_multiple: Create a new personilization for each recipient
          :type is_multiple: bool
          :param p: p is the Personalization object or Personalization object
                    index
          :type p: Personalization, integer, optional
          """
          if isinstance(bcc_email, str):
              bcc_email = Bcc(bcc_email, None)
          if isinstance(bcc_email, tuple):
              bcc_email = Bcc(bcc_email[0], bcc_email[1])
          if isinstance(bcc_email, Email):
              p = bcc_email.personalization
          self._set_emails(
              bcc_email,
              global_substitutions,
              is_multiple=is_multiple,
              p=p)