src/Message/Helper/MultipartHelper.php
public function getUniqueBoundary($mimeType)
    {
        $type = ltrim(strtoupper(preg_replace('/^(multipart\/(.{3}).*|.*)$/i', '$2-', $mimeType)), '-');
        return uniqid('----=MMP-' . $type . '.', true);
    }
public function getUniqueBoundary($mimeType)
    {
        $type = ltrim(strtoupper(preg_replace('/^(multipart\/(.{3}).*|.*)$/i', '$2-', $mimeType)), '-');
        return uniqid('----=MMP-' . $type . '.', true);
    }
public function getUniqueBoundary ( $ mimeType ) { $ type = ltrim ( strtoupper ( preg_replace ( '/^(multipart\/(.{3}).*|.*)$/i' , '$2-' , $ mimeType ) ) , '-' ) ; return uniqid ( '----=MMP-' . $ type . '.' , true ) ; }
Creates and returns a unique boundary.

@param string $mimeType first 3 characters of a multipart type are used,
e.g. REL for relative or ALT for alternative
@return string
Creates and returns a unique boundary .