public function getHeaders() {
		$headers = array();
		foreach ($this->headers as $name => $values) {
			foreach ($values as $value) {
				$headers[] = strtolower($name) . ': ' . $value;
			}
		}
		$headers[] = self::HEADER_KEY_CONTENT_LENGTH . ': ' . strlen($this->getBody());
		return $headers;
	}