/**
  * Test...
  *
  * @covers  Joomla\Filesystem\Helper::isJoomlaStream
  *
  * @return void
  */
 public function testIsJoomlaStream()
 {
     $this->assertTrue(Helper::isJoomlaStream('String'));
     $this->assertFalse(Helper::isJoomlaStream('unknown'));
 }
 /**
  * Determine the appropriate 'filename' of a file
  *
  * @param   string   $filename    Original filename of the file
  * @param   string   $mode        Mode string to retrieve the filename
  * @param   boolean  $use_prefix  Controls the use of a prefix
  * @param   boolean  $relative    Determines if the filename given is relative. Relative paths do not have JPATH_ROOT stripped.
  *
  * @return  string
  *
  * @since   11.1
  */
 public function _getFilename($filename, $mode, $use_prefix, $relative)
 {
     if ($use_prefix) {
         // Get rid of binary or t, should be at the end of the string
         $tmode = trim($mode, 'btf123456789');
         // Check if it's a write mode then add the appropriate prefix
         // Get rid of JPATH_ROOT (legacy compat) along the way
         if (in_array($tmode, Helper::getWriteModes())) {
             if (!$relative && $this->writeprefix) {
                 $filename = str_replace(JPATH_ROOT, '', $filename);
             }
             $filename = $this->writeprefix . $filename;
         } else {
             if (!$relative && $this->readprefix) {
                 $filename = str_replace(JPATH_ROOT, '', $filename);
             }
             $filename = $this->readprefix . $filename;
         }
     }
     return $filename;
 }