{
    "id": "http://trec-kba.org/schemas/v1.0/stream-item.json",
    "description": "An item in a stream corpus, i.e. a text corpus with time stamps that allow all the documents to be temporally ordered.",
    "type": "object",
    "$schema": "http://json-schema.org/draft-03/schema#",
    "extends": [{"$ref": "http://trec-kba.org/schemas/v1.0/corpus-item.json"}],
    "properties": {
        "stream_id": {
            "description": "Unique ID for instances of stream-item, assembled as \"%d-%s\" % (stream_time.epoch_ticks, doc_id)",
            "title": "Stream ID",
            "type": "string",
            "pattern": "^\\d+-[a-f0-9]{32}$",
            "required": true
        },
        "stream_time": {
            "description": "Time at which content entered data stream.  Derived differently for each stream source.",
            "type": "object",
            "properties": {
                "epoch_ticks": {
                    "description": "Seconds (and milliseconds) since the epoch January 1, 1970.",
		    "type": "float",
                    "required": true
		},
                "zulu_timestamp": {
                    "description": "Calculated from epoch_ticks in format %Y-%m-%dT%H:%M:%S.%fZ",
		    "type": "string",
		    "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}:\\d{2}\\.\\d{6}Z$",
                    "required": true
                    }
                }
            }
        }
    }