code/filesystem/mimetype/extension.php
protected function _getMimetype($extension)
    {
        $mimetypes = $this->_getMimetypes();

        return isset($mimetypes[$extension]) ? $mimetypes[$extension] : null;
    }
protected function _getMimetype($extension)
    {
        $mimetypes = $this->_getMimetypes();

        return isset($mimetypes[$extension]) ? $mimetypes[$extension] : null;
    }
protected function _getMimetype ( $ extension ) { $ mimetypes = $ this -> _getMimetypes ( ) ; return isset ( $ mimetypes [ $ extension ] ) ? $ mimetypes [ $ extension ] : null ; }
Return a mimetype for the given extension

@param  string $extension
@return string|null
Return a mimetype for the given extension