}

    /**
     * Checks if there is a previous page available.
     *
     * @return true if there is a previous page, false otherwise
     */
    public boolean isExistPrePage() {
        return existPrePage;
    }

    /**
     * Sets whether there is a previous page available.
     *
     * @param existPrePage true if there is a previous page, false otherwise
     */

That means that, clients using your API don't have to check if the value exists or not, they can **assume the field will always be there**, but just that in some cases it will have the default value of `None`.

The way to describe this in OpenAPI, is to mark that field as **required**, because it will always be there.

Because of that, the JSON Schema for a model can be different depending on if it's used for **input or output**:

     */
    @Nonnull
    <T> Optional<T> lookupOptional(Class<T> type, String name);

    /**
     * Performs a collection lookup for given typed components.
     *
     * @param type The component type.
     * @return The list of components. The list may be empty if no components found.
     * @param <T> The component type.

There is some assistance in the IDE for this plus a lot of validation that is applied at build time and on CI, but it is useful to keep these constraints in mind as well.

See [Gradle runtimes](runtimes.md) for a list of these runtimes and more details.

### Build execution model

    /** The total number of records */
    private int allRecordCount;

    /** The total number of pages */
    private int allPageCount;

    /** Whether there is a previous page available */
    private boolean existPrePage;

    /** Whether there is a next page available */
    private boolean existNextPage;

    /** List of page numbers for navigation */
    private List<Integer> pageNumberList;

     * @param type
     *            the hexcode of the name
     * @param scope
     *            the scope of the name
     * @return resolved addresses
     * @throws java.net.UnknownHostException
     *             if there is an error resolving the name
     */
    NetbiosAddress[] getNbtAllByAddress(String host, int type, String scope) throws UnknownHostException;

    /**

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     * @return the server's SID
     * @throws CIFSException if there is an error retrieving the server SID
     */
    SID getServerSid(CIFSContext tc, String authorityServerName) throws CIFSException;

    /**
     * This specialized method returns a Map of users and local groups for the
     * target server where keys are SIDs representing an account and each value

    }

    /**
     * Checks if there is a previous page available.
     *
     * @return true if there is a previous page, false otherwise
     */
    public boolean isExistPrePage() {
        return existPrePage;
    }

    /**
     * Sets whether there is a previous page available.
     *
     * @param existPrePage true if there is a previous page, false otherwise
     */

		logger.CriticalIf(context.Background(), Errorf("The seal algorithm '%s' is invalid for SSE-S3", sealedKey.Algorithm))
	}

	// There are two possibilities:
	// - We use a KMS -> There must be non-empty key ID and a KMS data key.
	// - We use a K/V -> There must be no key ID and no KMS data key.
	// Otherwise, the caller has passed an invalid argument combination.
	if keyID == "" && len(kmsKey) != 0 {