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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 _RequestBodyFromData(data):
 """Gets request body from data. When `data` is dict and list into unicode string; otherwise return `data` without making any change. :param (str, unicode, file-like stream object, dict, list or None) data: :rtype: str, unicode, file-like stream object, or None """

    if isinstance(data, six.string_types) or _IsReadableStream(data):
        return data
    elif isinstance(data, (dict, list, tuple)):
        
        json_dumped = json.dumps(data, separators=(',',':'))

        if six.PY2:
            return json_dumped.decode('utf-8')
        else:
            return json_dumped
    return None