CreateAttachment.
        Uploads an attachment.
        :param object upload_stream: Stream to upload
        :param str project: Project ID or project name
        :param str file_name: The name of the file
        :param str upload_type: Attachment upload type: Simple or Chunked
        :param str area_path: Target project Area Path
        :rtype: :class:`<AttachmentReference> <azure.devops.v5_0.work_item_tracking.models.AttachmentReference>`

def create_attachment(self, upload_stream, project=None, file_name=None, upload_type=None, area_path=None, **kwargs):
        """CreateAttachment.
        Uploads an attachment.
        :param object upload_stream: Stream to upload
        :param str project: Project ID or project name
        :param str file_name: The name of the file
        :param str upload_type: Attachment upload type: Simple or Chunked
        :param str area_path: Target project Area Path
        :rtype: :class:`<AttachmentReference> <azure.devops.v5_0.work_item_tracking.models.AttachmentReference>`
        """
        route_values = {}
        if project is not None:
            route_values['project'] = self._serialize.url('project', project, 'str')
        query_parameters = {}
        if file_name is not None:
            query_parameters['fileName'] = self._serialize.query('file_name', file_name, 'str')
        if upload_type is not None:
            query_parameters['uploadType'] = self._serialize.query('upload_type', upload_type, 'str')
        if area_path is not None:
            query_parameters['areaPath'] = self._serialize.query('area_path', area_path, 'str')
        if "callback" in kwargs:
            callback = kwargs["callback"]
        else:
            callback = None
        content = self._client.stream_upload(upload_stream, callback=callback)
        response = self._send(http_method='POST',
                              location_id='e07b5fa4-1499-494d-a496-64b860fd64ff',
                              version='5.0',
                              route_values=route_values,
                              query_parameters=query_parameters,
                              content=content,
                              media_type='application/octet-stream')
        return self._deserialize('AttachmentReference', response)