Java Unknown host Exception on calling Marketo API

I followed the marketo Sample code provide by them on github and i am getting the following error

Note: I am using proxy setting in my eclipse with port 80

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java.net.UnknownHostException: **my instance URL** at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:184) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:589) at sun.security.ssl.SSLSocketImpl.connect(SSLSocketImpl.java:666) at sun.net.NetworkClient.doConnect(NetworkClient.java:175) at sun.net.www.http.HttpClient.openServer(HttpClient.java:463) at sun.net.www.http.HttpClient.openServer(HttpClient.java:558) at sun.net.www.protocol.https.HttpsClient.<init>(HttpsClient.java:264) at sun.net.www.protocol.https.HttpsClient.New(HttpsClient.java:367) at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.getNewHttpClient(AbstractDelegateHttpsURLConnection.java:191) at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1156) at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1050) at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:177) at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1564) at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1492) at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480) at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:347) at Leads.getToken(Leads.java:97) at Leads.getData(Leads.java:40) at Leads.main(Leads.java:30)