ce,
      "filename" should use "/" characters to separate path
      segments, and may not be an absolute path (i.e., it may not
      begin with "/").

      If "module_relative" is False, then the given file paths are
      interpreted as os-specific paths.  These paths may be absolute
      or relative (to the current working directory).

    package
      A Python package or the name of a Python package whose directory
      should be used as the base directory for module relative paths.
      If "package" is not specified, then the calling module's
      directory is used as the base directory for module relative
      filenames.  It is an error to specify "package" if
      "module_relative" is False.

    setUp
      A set-up function.  This is called before running the
      tests in each file. The setUp function will be passed a DocTest
      object.  The setUp function can access the test globals as the
      globs attribute of the test passed.

    tearDown
      A tear-down function.  This is called after running the
      tests in each file.  The tearDown function will be passed a DocTest
      object.  The tearDown function can access the test globals as the
      globs attribute of the test passed.

    globs
      A dictionary containing initial global variables for the tests.

    optionflags
      A set of doctest option flags expressed as an integer.

    parser
      A DocTestParser (or subclass) that should be used to extract
      tests from the files.

    encoding
      An encoding that will be used to convert the files to unicode.
    rV