public function getBlobInstance($containerName = '', $blobName = '', $snapshotId = null, $leaseId = null, $additionalHeaders = array())
    {
        Assertion::notEmpty($containerName, 'Container name is not specified');
        self::assertValidContainerName($containerName);
        Assertion::notEmpty($blobName, 'Blob name is not specified.');
        self::assertValidRootContainerBlobName($containerName, $blobName);

        $query = array();
        if (!is_null($snapshotId)) {
            $query['snapshot'] = $snapshotId;
        }

        $headers = array();
        if (!is_null($leaseId)) {
            $headers['x-ms-lease-id'] = $leaseId;
        }
        foreach ($additionalHeaders as $key => $value) {
            $headers[$key] = $value;
        }

        $resourceName = self::createResourceName($containerName , $blobName);

        $response = $this->performRequest($resourceName, $query, 'HEAD', $headers, false, null, self::RESOURCE_BLOB, self::PERMISSION_READ);
        if ( ! $response->isSuccessful()) {
            throw new BlobException($this->getErrorMessage($response, 'Resource could not be accessed.'));
        }

        $metadata = $this->parseMetadataHeaders($response->getHeaders());

        return new BlobInstance(
            $containerName,
            $blobName,
            $snapshotId,
            $response->getHeader('Etag'),
            $response->getHeader('Last-modified'),
            $this->getBaseUrl() . '/' . $containerName . '/' . $blobName,
            $response->getHeader('Content-Length'),
            $response->getHeader('Content-Type'),
            $response->getHeader('Content-Encoding'),
            $response->getHeader('Content-Language'),
            $response->getHeader('Cache-Control'),
            $response->getHeader('x-ms-blob-type'),
            $response->getHeader('x-ms-lease-status'),
            false,
            $metadata
        );
    }