diff --git a/lib/index.js b/lib/index.js
index 17fcab8..3f20b96 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -188,7 +188,7 @@ var generateAdvancedMappings = function(mappingFunctions) {
         return cb(new Error('Argument error in getDocumentById: the first argument must be a numeric id'));
       }
 
-      if(typeof(config) === 'function') {
+      if(isFunction(config)) {
         config = config();
       }
       if (!config.file) {
diff --git a/sample.js b/sample.js
index fc662fa..c068c89 100644
--- a/sample.js
+++ b/sample.js
@@ -11,7 +11,7 @@ Anyfetch.getAccessToken(APP_ID, APP_SECRET, code, function(err, accessToken) {
 
 	client.getSubcompanyById(123, cb);
 
-	client.postUsers({ endpoint: 'rere' }, cb );
+	client.postUser({ name: 'Rick' }, cb );
 
 	client.updateCompany(cbErr);
 	client.resetCompany(cbErr);