class PHPUnit_Util_Filesystem

class PHPUnit_Util_Filesystem {

  /**
   * @var array
   */
  protected static $buffer = array();

  /**
   * Maps class names to source file names:
   *   - PEAR CS:   Foo_Bar_Baz -> Foo/Bar/Baz.php
   *   - Namespace: Foo\Bar\Baz -> Foo/Bar/Baz.php
   *
   * @param  string $className
   * @return string
   * @since  Method available since Release 3.4.0
   */
  public static function classNameToFilename($className) {
    return str_replace(array(
      '_',
      '\\',
    ), DIRECTORY_SEPARATOR, $className) . '.php';
  }

}