@CollectionSize.Require(absent = ZERO)
  public void testKeySetIteratorRemove() {
    int initialSize = getNumElements();
    Iterator<K> iterator = getMap().keySet().iterator();
    iterator.next();
    iterator.remove();
    assertEquals(initialSize - 1, getMap().size());
    assertEquals(initialSize - 1, getMap().inverse().size());
  }

`Field` works the same way as `Query`, `Path` and `Body`, it has all the same parameters, etc.

/// note | "Technical Details"

Actually, `Query`, `Path` and others you'll see next create objects of subclasses of a common `Param` class, which is itself a subclass of Pydantic's `FieldInfo` class.

And Pydantic's `Field` returns an instance of `FieldInfo` as well.

        Iterator<TransferResourceAndSize> entries = transfers.values().iterator();
        while (entries.hasNext()) {
            TransferResourceAndSize entry = entries.next();
            // just in case, make sure 0 <= complete <= total
            long complete = Math.max(0, entry.transferredBytes);
            long total = Math.max(complete, entry.resource.getContentLength());

This would be typical after a user initiates a force refresh by a pull to refresh type action.

```java
    val urlIterator = cache.urls()
    while (urlIterator.hasNext()) {
      if (urlIterator.next().startsWith("https://www.google.com/")) {
        urlIterator.remove()
      }
    }
```

### Troubleshooting

1. Valid cacheable responses are not being cached

  interface Callback {
    fun onEvent(
      id: String?,
      type: String?,
      data: String,
    )

    fun onRetryChange(timeMs: Long)
  }

  /**
   * Process the next event. This will result in a single call to [Callback.onEvent] *unless* the
   * data section was empty. Any number of calls to [Callback.onRetryChange] may occur while
   * processing an event.
   *

            @Override
            @CheckForNull
            protected Entry<Range<K>, V> computeNext() {
              if (backingItr.hasNext()) {
                RangeMapEntry<K, V> entry = backingItr.next();
                if (entry.getUpperBound().compareTo(subRange.lowerBound) <= 0) {
                  return endOfData();
                }

				t.Errorf("Case %d: test failed: %d %d %d %d %d", i, o, l, skip, sn, ps)
			}
		}

		kb32 := int64(32) * humanize.KiByte
		if test.decSz >= (64+32)*humanize.KiByte {
			// Skip the first 32Kib, and read the next 64Kib
			o, l, skip, sn, ps, err := test.oi.GetDecryptedRange(&HTTPRangeSpec{false, kb32, 3*kb32 - 1})
			if err != nil {
				t.Errorf("Case %d: unexpected err: %v", i, err)
			}
			rLen := (pkgSz + 32) * 2

        if (r1.size() != r2.size()) {
            return false;
        }

        for (Iterator<RemoteRepository> it1 = r1.iterator(), it2 = r2.iterator(); it1.hasNext(); ) {
            if (!repositoryEquals(it1.next(), it2.next())) {
                return false;
            }
        }

        return true;
    }

    public static int repositoriesHashCode(List<RemoteRepository> repositories) {
        int result = 17;

				// of length j at offset i and ask for
				// Next(k), we get the right bytes.
				buf := NewBuffer(b[0:j])
				n, _ := buf.Read(tmp[0:i])
				if n != i {
					t.Fatalf("Read %d returned %d", i, n)
				}
				bb := buf.Next(k)
				want := k
				if want > j-i {
					want = j - i
				}
				if len(bb) != want {
					t.Fatalf("in %d,%d: len(Next(%d)) == %d", i, j, k, len(bb))
				}

		t.Fatalf("tw.Write: %v", err)
	}
	if err := tw.Close(); err != nil {
		t.Fatalf("tw.Close: %v", err)
	}

	// Read it back.
	tr := NewReader(&b)
	rHdr, err := tr.Next()
	if err != nil {
		t.Fatalf("tr.Next: %v", err)
	}
	if !reflect.DeepEqual(rHdr, hdr) {
		t.Errorf("Header mismatch.\n got %+v\nwant %+v", rHdr, hdr)
	}
	rData, err := io.ReadAll(tr)
	if err != nil {