src/HTTP/Request2.php
public function addPostParameter($name, $value = null)
    {
        if (!is_array($name)) {
            $this->postParams[$name] = $value;
        } else {
            foreach ($name as $k => $v) {
                $this->addPostParameter($k, $v);
            }
        }
        if (empty($this->headers['content-type'])) {
            $this->setHeader('content-type', 'application/x-www-form-urlencoded');
        }

        return $this;
    }
public function addPostParameter($name, $value = null)
    {
        if (!is_array($name)) {
            $this->postParams[$name] = $value;
        } else {
            foreach ($name as $k => $v) {
                $this->addPostParameter($k, $v);
            }
        }
        if (empty($this->headers['content-type'])) {
            $this->setHeader('content-type', 'application/x-www-form-urlencoded');
        }

        return $this;
    }
Adds POST parameter(s) to the request.

@param string|array $name  parameter name or array ('name' => 'value')
@param mixed        $value parameter value (can be an array)

@return   HTTP_Request2