Fix

node_modules/shiki/samples/apex.sample

@@ -0,0 +1,19 @@
+public class EmailManager {
+
+    public static void sendMail(String address, String subject, String body) {
+        Messaging.SingleEmailMessage mail = new Messaging.SingleEmailMessage();
+        String[] toAddresses = new String[] {address};
+        mail.setToAddresses(toAddresses);
+        mail.setSubject(subject);
+        mail.setPlainTextBody(body);
+        Messaging.sendEmail(new Messaging.SingleEmailMessage[] { mail });
+    }
+
+}
+
+String address = 'YOUR_EMAIL_ADDRESS';
+String subject = 'Speaker Confirmation';
+String body = 'Thank you for speaking at the conference.';
+EmailManager.sendMail(address, subject, body);
+
+// From http://ccoenraets.github.io/salesforce-developer-workshop/Creating-an-Apex-Class.html