downgrade to kirby v3

vendor/ml/json-ld/JsonLdSerializable.php

@@ -0,0 +1,38 @@
+<?php
+
+/*
+ * (c) Markus Lanthaler <mail@markus-lanthaler.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace ML\JsonLD;
+
+/**
+ * The JsonLdSerializable interface
+ *
+ * Objects implementing JsonLdSerializable can be serialized to JSON-LD.
+ *
+ * @author Markus Lanthaler <mail@markus-lanthaler.com>
+ */
+interface JsonLdSerializable
+{
+    /**
+     * Convert to expanded and flattened JSON-LD
+     *
+     * The result can then be serialized to JSON-LD by {@see JsonLD::toString()}.
+     *
+     * @param boolean $useNativeTypes If set to true, native types are used
+     *                                for xsd:integer, xsd:double, and
+     *                                xsd:boolean, otherwise typed strings
+     *                                will be used instead.
+     *
+     * @return mixed Returns data which can be serialized by
+     *               {@see JsonLD::toString()} (which is a value of any type
+     *               other than a resource) to expanded JSON-LD.
+     *
+     * @see JsonLD::toString()
+     */
+    public function toJsonLd($useNativeTypes = true);
+}