use extend for parsing options

lib/api/graph.js

@@ -1,4 +1,5 @@
 var client = require("../client");
+var extend = require("extend");
 var json = require("../json");
 var querystring = require("querystring");
 
@@ -91,8 +92,12 @@ function createEmbed(graphJSON, options, callback){
         callback = options;
         options = {};
     }
-    var body = options || {};
-    body.graph_json = JSON.stringify(graphJSON);
+    var body = {
+        graph_json: JSON.stringify(graphJSON)
+    };
+    // Use `extend` to merge `options` into `body`
+    // DEV: `extend` will ignore any properties whose value is `undefined`
+    extend(body, options || {});
 
     // Create the request
     var params = {
@@ -108,8 +113,8 @@ module.exports = {
     createEmbed: createEmbed,
     getUsage: function(){
         return [
-          "  dogapi graph snapshot <query> <from> <to> [--events <event-query>]",
-          "  dogapi graph create_embed <graph_json> [--timeframe <timeframe>] [--size <size>] [--legend <legend>] [--title <title>]"
+            "  dogapi graph snapshot <query> <from> <to> [--events <event-query>]",
+            "  dogapi graph create_embed <graph_json> [--timeframe <timeframe>] [--size <size>] [--legend <legend>] [--title <title>]"
         ];
     },
     getHelp: function(){
@@ -142,7 +147,7 @@ module.exports = {
                 legend: args["legend"],
                 title: args["title"]
             };
-            createEmbed(graph_json, timeframe, size, legend, title, callback);
+            createEmbed(graph_json, options, callback);
         } else {
             callback("unknown subcommand or arguments try `dogapi graph --help` for help", false);
         }