def METHOD_NAME(app):
    # prologue with trailing line break
    prolog = 'this is rst_prolog\nhello reST!\n'
    content = StringList([':mod:`foo`', '-' * 10, '', 'hello'], '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, ':mod:`foo`'),
                                      ('dummy.rst', 1, '----------'),
                                      ('dummy.rst', 2, ''),
                                      ('dummy.rst', 3, 'hello')]