// We specifically break this out so that we can use defer here safely.
	// One option is to break this out into a new function instead, but
	// there's so much local iteration state used below that this turns out
	// to be cleaner.
	defer i.mu.Unlock()

	var oldEntry *entry[K, V]
	if n != nil {
		oldEntry = n.entry()
		if v, ok := oldEntry.lookup(key, ht.keyEqual); ok {

 * but not by just the column key.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in

			switch {
			case k == nil:
				count = "no iteration variables"
			case v == nil:
				count = "one iteration variable"
			default:
				count = "two iteration variables"
			}
			check.softErrorf(&x, InvalidIterVar, "range over %s must have %s", &x, count)
		}
		key, val = k, v
	}

	// Open the for-statement block scope now, after the range clause.

			switch {
			case k == nil:
				count = "no iteration variables"
			case v == nil:
				count = "one iteration variable"
			default:
				count = "two iteration variables"
			}
			check.softErrorf(&x, InvalidIterVar, "range over %s must have %s", &x, count)
		}
		key, val = k, v
	}

	// Open the for-statement block scope now, after the range clause.

          public int size() {
            return Iterators.size(iterator());
          }

          @Override
          public boolean isEmpty() {
            return !iterator().hasNext();
          }
        };
      }

      Iterator<Entry<Range<K>, V>> entryIterator() {
        if (subRange.isEmpty()) {
          return Iterators.emptyIterator();
        }
        Cut<K> cutToStart =

 * while adding a new pair.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap, even if the
 * underlying map and {@link #createCollection()} method return threadsafe classes. Concurrent read
 * operations will work correctly. To allow concurrent update operations, wrap your multimap with a
 * call to {@link Multimaps#synchronizedMultimap}.
 *

 * while adding a new pair.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap, even if the
 * underlying map and {@link #createCollection()} method return threadsafe classes. Concurrent read
 * operations will work correctly. To allow concurrent update operations, wrap your multimap with a
 * call to {@link Multimaps#synchronizedMultimap}.
 *

 * entries may be counted in {@link Cache#size}, but will never be visible to read or write
 * operations.
 *
 * <p>Certain cache configurations will result in the accrual of periodic maintenance tasks which
 * will be performed during write operations, or during occasional read operations in the absence of
 * writes. The {@link Cache#cleanUp} method of the returned cache will also perform maintenance, but

 * but not by just the column key.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in

				return nil, err
			}
			// If the target version is a pseudo-version, it may not be
			// included when iterating over prior versions using reqs.Previous.
			// Insert it into the right place in the iteration.
			// If v is excluded, p should be returned again by reqs.Previous on the next iteration.
			if v := max[r.Path]; reqs.Max(r.Path, v, r.Version) != v && reqs.Max(r.Path, p.Version, v) != p.Version {
				p.Version = v