### Description

InternalComposite.formatObject() can throw an IllegalArgumentException if the format to be applied to a composite key leads to a loss of information (eg, a date histogram with a width of one day is then given a date format of 'YYYY-mm', meaning that multiple buckets from the same month would produce the same key).  This is currently only checked during serialization, meaning that we can do a great deal of work building aggregations only to then throw the result away at the end.  This also causes a problem for converting the `_search` endpoint to using chunked xcontent serialization, as the HTTP response code is the first thing sent back, and so errors that occur during later serialization don't get handled correctly.
server/src/test/java/org/elasticsearch/search/aggregations/bucket/composite/InternalCompositeTests.java
import java.io.IOException;
import java.time.ZoneOffset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.TreeSet;
import java.util.stream.IntStream;
import static com.carrotsearch.randomizedtesting.RandomizedTest.randomAsciiLettersOfLengthBetween;
import static java.util.Collections.emptyList;
import static java.util.Collections.emptyMap;
import static java.util.stream.Collectors.toList;
import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.greaterThan;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.lessThan;
import static org.hamcrest.Matchers.lessThanOrEqualTo;
public class InternalCompositeTests extends InternalMultiBucketAggregationTestCase<InternalComposite> {
    private List<String> sourceNames;
    private List<DocValueFormat> formats;
    private int[] reverseMuls;
    private MissingOrder[] missingOrders;
    private int[] types;
    private int size;
    private static DocValueFormat randomDocValueFormat(boolean isLong) {