Issue in facebook.stream.addlike in fbConnect for Android?

Question

I'm using fbConnect for Android for facebook functionality for my app. When I'm using facebook.stream.addlike I get error_code 100 and "Missing post identifier" as error detail. Find my code snippet below.

Map params = new HashMap(); FBSession fbSession = FBSession.getSession(); params.put("post_id,", postId);

 String uid = fbSession.getUid().toString();
 params.put("uid", fbSession.getUid().toString());

 //Map<String, String> params = Collections.singletonMap("post_id,", postId);
 FBRequest.requestWithDelegate(FacebookManager.this).callPost("facebook.stream.addLike" , params);

I have verified that proper values are sent in post_id and uid. Please let me know what I'm missing?