Add AuthorityFieldInterface

Author: danmichaelo

src/Fields/AuthorityFieldInterface.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Scriptotek\Marc\Fields;
+
+interface AuthorityFieldInterface extends FieldInterface
+{
+    /**
+     * The control number of the authority record.
+     *
+     * @return string|null
+     */
+    public function getId(): ?string;
+
+    /**
+     * The type of authority record.
+     *
+     * @return string
+     */
+    public function getType(): string;
+}