unwind batching

statement.json

{
	"statements": [
		{
			"statement": "UNWIND {nodes} as x MERGE (o:Object {um: x.umid}) SET o.value = x.value, o.updated = timestamp()",
			"parameters": {
				"nodes": [
					{
						"umid": 1,
						"value": "bla bla"
					},
					{
						"umid": 2,
						"value": "bla bla"
					}
				]
			}
		}
	]
}