Feat: support example body undefined

Author: joolfe

lib/index.js

@@ -562,7 +562,7 @@ function parseExamples (bodies, language) {
 function safeSampleParse (body, name, language) {
   if (language === 'json') {
     const errors = []
-    const parsedBody = jsonc.parse((body === null || body.trim().length === 0) ? '{}' : body, errors)
+    const parsedBody = jsonc.parse((body == null || body.trim().length === 0) ? '{}' : body, errors)
     if (errors.length > 0) {
       throw new Error('Error parsing response example "' + name + '"')
     }