docs: def from_EmailMessage(cls, message):
          """Create a Mail object from an instance of
          email.message.EmailMessage.
  
          :type message: email.message.EmailMessage
          :rtype: Mail
          """
          mail = cls(
              from_email=Email(message.get('From')),
              subject=message.get('Subject'),
              to_emails=Email(message.get('To')),
          )
          try:
              body = message.get_content()
          except AttributeError:
              # Python2
              body = message.get_payload()
          mail.add_content(Content(
              message.get_content_type(),
              body.strip()
          ))
          for k, v in message.items():
              mail.add_header(Header(k, v))
          return mail