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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(response):
 """ Return charset from ``response`` or default charset. :rtype: str """

    # Set default charset
    charset = DEFAULT_CHARSET

    m = re.findall(r';charset=(.*)', response.get('mimeType', ''))
    if m:
        charset = m[0]

    return charset