LLM OCP API: Fix type errors

Signed-off-by: Marcel Klehr <mklehr@gmx.net>

lib/public/LanguageModel/AbstractLanguageModelTask.php

@@ -6,6 +6,7 @@ use OC\LanguageModel\Db\Task;
 
 abstract class AbstractLanguageModelTask implements ILanguageModelTask {
 	protected ?int $id;
+	protected ?string $output;
 	protected int $status = ILanguageModelTask::STATUS_UNKNOWN;
 
 	final public function __construct(
@@ -26,6 +27,20 @@ abstract class AbstractLanguageModelTask implements ILanguageModelTask {
 
 	abstract public function getType(): string;
 
+	/**
+	 * @return string|null
+	 */
+	final public function getOutput(): ?string {
+		return $this->output;
+	}
+
+	/**
+	 * @param string|null $output
+	 */
+	final public function setOutput(?string $output): void {
+		$this->output = $output;
+	}
+
 	/**
 	 * @return int
 	 */

lib/public/LanguageModel/ILanguageModelTask.php

@@ -16,6 +16,11 @@ interface ILanguageModelTask extends \JsonSerializable {
 		TopicsTask::TYPE => TopicsTask::class,
 	];
 
+	public function visitProvider(ILanguageModelProvider $provider): string;
+
+	public function canUseProvider(ILanguageModelProvider $provider): bool;
+
+
 	/**
 	 * @return string
 	 */
@@ -47,14 +52,14 @@ interface ILanguageModelTask extends \JsonSerializable {
 	public function getInput(): string;
 
 	/**
-	 * @param string $output
+	 * @param string|null $output
 	 */
-	public function setOutput(string $output): void;
+	public function setOutput(?string $output): void;
 
 	/**
-	 * @return string
+	 * @return null|string
 	 */
-	public function getOutput(): string;
+	public function getOutput(): ?string;
 
 	/**
 	 * @return string