}
public void arithmenticProjectionOperationWithoutAlias() {
String fieldName = "a";
ProjectionOperationBuilder operation = new ProjectionOperation().and(fieldName).plus(1);
DBObject dbObject = operation.toDBObject(Aggregation.DEFAULT_CONTEXT);
DBObject projectClause = DBObjectTestUtils.getAsDBObject(dbObject, PROJECT);
DBObject oper = exctractOperation(fieldName, projectClause);
assertThat(oper.containsField(ADD), is(true));
assertThat(oper.get(ADD), is((Object) Arrays.<Object> asList("$a", 1)));