IllegalArgumentException.class, () -> checkArgument(false, "A %s C", (Object) null));
    assertThat(e).hasMessageThat().isEqualTo("A null C");
  }

  @J2ktIncompatible // TODO(b/319404022): Allow passing null array as varargs
  public void testCheckArgument_singleNullArray_failure() {
    IllegalArgumentException e =
        assertThrows(

            IllegalArgumentException.class, () -> checkArgument(false, "A %s C", (Object) null));
    assertThat(e).hasMessageThat().isEqualTo("A null C");
  }

  @J2ktIncompatible // TODO(b/319404022): Allow passing null array as varargs
  public void testCheckArgument_singleNullArray_failure() {
    IllegalArgumentException e =
        assertThrows(

We can declare all that without having to modify the original `APIRouter` by passing those parameters to `app.include_router()`:

```Python hl_lines="14-17" title="app/main.py"
{!../../docs_src/bigger_applications/app/main.py!}
```

   * aren't annotated nullable (according to the rules of {@link NullPointerTester}). In details:
   *
   * <ul>
   *   <li>All non-private static methods are checked such that passing null for any parameter
   *       that's not annotated nullable should throw {@link NullPointerException}.
   *   <li>If there is any non-private constructor or non-private static factory method declared by

   * elements.
   *
   * <p>To cycle over the elements {@code n} times, use the following: {@code
   * Iterables.concat(Collections.nCopies(n, Arrays.asList(elements)))}
   *
   * <p><b>Java 8+ users:</b> If passing a single element {@code e}, the {@code Stream} equivalent
   * of this method is {@code Stream.generate(() -> e)}. Otherwise, put the elements in a collection

      Throwable cause = e.getCause();
      if (policy.isExpectedType(cause)) {
        return;
      }
      throw new AssertionError(
          String.format(
              "wrong exception thrown from %s when passing null to %s parameter at index %s.%n"
                  + "Full parameters: %s%n"
                  + "Actual exception message: %s",
              invokable,
              invokable.getParameters().get(paramIndex).getType(),

   *
   * @param formal The type whose type variables or itself is mapped to other type(s). It's almost
   *     always a bug if {@code formal} isn't a type variable and contains no type variable. Make
   *     sure you are passing the two parameters in the right order.
   * @param actual The type that the formal type variable(s) are mapped to. It can be or contain yet
   *     other type variables, in which case these type variables will be further resolved if

| _Required_    | _No_                                               |

### Policy

		if err != nil {
			return nil, err
		}
	}
	if sysStat != nil {
		return h, sysStat(fi, h, doNameLookups)
	}
	return h, nil
}

// FileInfoNames extends [fs.FileInfo].
// Passing an instance of this to [FileInfoHeader] permits the caller
// to avoid a system-dependent name lookup by specifying the Uname and Gname directly.
type FileInfoNames interface {
	fs.FileInfo
	// Uname should give a user name.

       <artifactId>okio</artifactId>
       <version>1.4.0</version>
     </dependency>
     ```

 *  **`Request.Builder` no longer accepts null if a request body is required.**
    Passing null will now fail for request methods that require a body. Instead
    use an empty body such as this one:

    ```java
        RequestBody.create(null, new byte[0]);
    ```