e := f.updateCache.find(parent.Key())
					if e == nil || e.Compacted {
						foundAny = true
						break
					}
					next := f.updateCache.searchParent(parent)
					if next == nil {
						foundAny = true
						break
					}
					parent = *next
				}
				if !foundAny {
					// Add non-compacted empty entry.
					f.updateCache.replaceHashed(h, &thisHash, dataUsageEntry{})
				}
			}

    map.put(2, "b");
    Iterator<Entry<String, Integer>> inverseEntryItr = map.inverse().entrySet().iterator();
    Entry<String, Integer> entry = inverseEntryItr.next();
    entry.setValue(3);
    assertEquals(immutableEntry("b", 2), inverseEntryItr.next());
    assertFalse(inverseEntryItr.hasNext());
    assertThat(map.entrySet())
        .containsExactly(immutableEntry(2, "b"), immutableEntry(3, "a"))
        .inOrder();

    checkNotNull(appendable);
    if (parts.hasNext()) {
      appendable.append(toString(parts.next()));
      while (parts.hasNext()) {
        appendable.append(separator);
        appendable.append(toString(parts.next()));
      }
    }
    return appendable;
  }

  /**

    if (comparator == null) {
      comparator = NATURAL_ORDER;
    }
    Iterator<Entry<K, V>> entryItr = navigableMap.entrySet().iterator();
    Entry<K, V> prevEntry = entryItr.next();
    while (entryItr.hasNext()) {
      Entry<K, V> nextEntry = entryItr.next();
      assertTrue(comparator.compare(prevEntry.getKey(), nextEntry.getKey()) < 0);
      prevEntry = nextEntry;
    }
  }

  }

  private Entry<K, V> getEntryNullReplaces() {
    Iterator<Entry<K, V>> entries = getSampleElements().iterator();
    for (int i = 0; i < getNullLocation(); i++) {
      entries.next();
    }
    return entries.next();
  }

  /**
   * @return an array of the proper size with {@code null} as the value of the middle element.
   */
  protected Entry<K, V>[] createArrayWithNullValue() {

    map.put(2, "b");
    Iterator<Entry<String, Integer>> inverseEntryItr = map.inverse().entrySet().iterator();
    Entry<String, Integer> entry = inverseEntryItr.next();
    entry.setValue(3);
    assertEquals(immutableEntry("b", 2), inverseEntryItr.next());
    assertFalse(inverseEntryItr.hasNext());
    assertThat(map.entrySet())
        .containsExactly(immutableEntry(2, "b"), immutableEntry(3, "a"))
        .inOrder();

        // Given
        Smb2CancelRequest request = new Smb2CancelRequest(mockConfig, 1L, 0L);

        // When
        ServerMessageBlock2Request<?> next = request.getNext();

        // Then
        assertNull(next, "Cancel requests should not have next requests in chain");
    }

    @Test
    @DisplayName("Test getOverrideTimeout returns null")
    void testGetOverrideTimeout() {
        // Given

        }

        return false
      }

      override fun next(): String {
        if (!hasNext()) throw NoSuchElementException()
        val result = nextUrl!!
        nextUrl = null
        canRemove = true
        return result
      }

      override fun remove() {
        check(canRemove) { "remove() before next()" }
        delegate.remove()
      }
    }
  }

I'll show you some concrete examples in the next chapters.

---

Then the next concepts to consider are all about the program running your actual API (e.g. Uvicorn).

## Program and Process { #program-and-process }

}

// Results returns the results from the remote server one by one.
// If any error is returned by the callback, the stream will be canceled.
// If the context is canceled, the stream will be canceled.
func (s *Stream) Results(next func(b []byte) error) (err error) {
	done := false
	defer func() {
		if s.cancel != nil {
			s.cancel(err)
		}

		if !done {
			// Drain channel.
			for range s.responses {
			}
		}
	}()