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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_charset(content_type):
 """Function used to retrieve the charset from a content-type.If there is no charset in the content type then the charset defined on DEFAULT_CHARSET will be returned :param content_type: A string containing a Content-Type header :returns: A string containing the charset """

    if not content_type:
        return DEFAULT_CHARSET

    matched = _get_charset_re.search(content_type)
    if matched:
        # Extract the charset and strip its double quotes
        return matched.group('charset').replace('"', '')
    return DEFAULT_CHARSET