Client/HttpClient.php
function post($uri, array $data = null)
    {
        $opts = $this->buildOpts('POST');
        if ($data !== null) {
            $opts['http']['content'] = json_encode($data);
        }
        return $this->execute($uri, $opts);
    }
function post($uri, array $data = null)
    {
        $opts = $this->buildOpts('POST');
        if ($data !== null) {
            $opts['http']['content'] = json_encode($data);
        }
        return $this->execute($uri, $opts);
    }
@param string $uri
@param array  $data

@return string