def METHOD_NAME(app):
    # prolog having CR at tail
    prolog = 'this is rst_prolog\nhello reST!\n'
    content = StringList(['hello Sphinx world',
                          'Sphinx is a document generator'],
                         'dummy.rst')
    prepend_prolog(content, prolog)
    assert list(content.xitems()) == [('<rst_prolog>', 0, 'this is rst_prolog'),
                                      ('<rst_prolog>', 1, 'hello reST!'),
                                      ('<generated>', 0, ''),
                                      ('dummy.rst', 0, 'hello Sphinx world'),
                                      ('dummy.rst', 1, 'Sphinx is a document generator')]