//    (hypothetical) unsafe read by our caller. Note: adding 'volatile' does not fix this issue,
  //    it would just add an edge such that if done() observed non-null, then it would also
  //    definitely observe all earlier writes, but we still have no guarantee that done() would see
  //    the initial write (just stronger guarantees if it does).
  //

# Header Parameter Models { #header-parameter-models }

If you have a group of related **header parameters**, you can create a **Pydantic model** to declare them.

This would allow you to **re-use the model** in **multiple places** and also to declare validations and metadata for all the parameters at once. 😎

/// note

This is supported since FastAPI version `0.115.0`. 🤓

///

# That provides general hygiene, including avoiding release errors:
#
# Preparing to update Javadoc and JDiff for the release...
# error: Your local changes to the following files would be overwritten by checkout:
#         integration-tests/gradle/gradle/wrapper/gradle-wrapper.jar
#         integration-tests/gradle/gradle/wrapper/gradle-wrapper.properties
#         integration-tests/gradle/gradlew

would be valid to use as a **FastAPI** dependency.

In fact, FastAPI uses those two decorators internally.

///

## A database dependency with `yield` { #a-database-dependency-with-yield }

For example, you could use this to create a database session and close it after finishing.

    }

    boolean empty;
    if (effectiveRange.isEmpty()) {
      empty = true;
    } else {
      /*
       * requireNonNull is safe because the effectiveRange operations above would have thrown or
       * effectiveRange.isEmpty() would have returned true.
       */
      C afterLower = requireNonNull(range.lowerBound.leastValueAbove(domain));
      C beforeUpper = requireNonNull(range.upperBound.greatestValueBelow(domain));

- `aws:username` - This is a string containing the friendly name of the current user, this value would point to STS temporary credential in `AssumeRole`ed requests, use `jwt:preferred_username` in case of OpenID connect and `ldap:username` in case of AD/LDAP. *aws:userid* is an alias to *aws:username* in MinIO.

/// tip

You can write Markdown in the `description` field and it will be rendered in the output.

///

With this configuration, the automatic API docs would look like:

<img src="/img/tutorial/metadata/image01.png">

## License identifier { #license-identifier }

     * silently {@link #addNode(Object) add} {@code nodeU} and {@code nodeV} to the graph.
     *
     * @return this {@code Builder} object
     * @throws IllegalArgumentException if the introduction of the edge would violate {@link
     *     #allowsSelfLoops()}
     */
    @CanIgnoreReturnValue
    public ImmutableValueGraph.Builder<N, V> putEdgeValue(N nodeU, N nodeV, V value) {

   *
   * Since these fields are non-final that means that TimeoutFuture is not being 'safely published',
   * thus a motivated caller may be able to expose the reference to another thread that would then
   * call cancel() and be unable to cancel the delegate.
   * There are a number of ways to solve this, none of which are very pretty, and it is currently

						kvs = jstream.KVS{jstream.KV{Key: "_1", Value: mv.Value}}
					}
					all = append(all, kvs)
				}
				// We don't need the input any more.
				//nolint:staticcheck // SA6002 Using pointer would allocate more since we would have to copy slice header before taking a pointer.
				r.bufferPool.Put(in.input)
				in.input = nil
				in.err = d.Err()
				in.dst <- all
			}
		}()
	}
}