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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_dc_keywords(index_page):
 """ Return list of `keywords` parsed from Dublin core. Args: index_page (str):
 Content of the page as UTF-8 string Returns: list: List of :class:`.SourceString` objects. """

    keyword_lists = (
        keyword_list.split()
        for keyword_list in parse_meta(index_page, "dc.keywords", "DC")
    )

    return [
        SourceString(keyword, source="DC")
        for keyword in sum(keyword_lists, [])  # flattern the list
    ]