List<Entity> entities = newArrayListWithExpectedSize(input.getRecords().size());
for (ProcessDataRecord record : input.getRecords()) {
Entity e = null;
InsertItem keyItem = stmt.keyItem();
if (keyItem == null) {
e = new Entity(stmt.getKind());
} else {
// TODO : add validation to make sure it always returns a key
e = new Entity((Key) keyItem.getE().evaluate(record).getPayload());
}
for(InsertItem item : stmt.propertyItems()) {
Object val = item.getE().evaluate(record).getPayload(); // evaluation type
val = DatastoreUtil.toDatastoreType(val); // datastore type