Handling post request using Unirest Library (PHP)

I am presently working with the unirest php library, i initiated a post request from http://localhost/path/post to a certain url, let's say http://localhost/path/handler, how do i get the post array sent from http://localhost/path/post on http://localhost/path/handler, i tried using the $_POST[] superglobal array, it is returning NULL ?