+ /**
+ * Get entire additionalContent array.
+ *
+ * @return mixed[]
+ */
+ public function getAdditionalContent(): array
+ {
+ return $this->additionalContent;
+ }
+
+ /**
+ * Set a single entry in additionalContent, by key.
+ *
+ * @param string $key
+ * @param mixed|null $value Any type of value can be set.
+ *
+ * @return $this
+ */
+ public function addAdditionalContentEntry(string $key, $value): self
+ {
+ $this->additionalContent[$key] = $value;
+
+ return $this;
+ }
+
+ /**
+ * Get a single entry in additionalContent, by key.
+ *
+ * @param string $key
+ * @param mixed|null $default
+ *
+ * @return mixed|null can be any type or even null.
+ */
+ public function getAdditionalContentEntry(string $key, $default = null)
+ {
+ return array_key_exists($key, $this->additionalContent) ? $this->additionalContent[$key] : $default;
+ }
+