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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 parse_body_arguments( content_type: str, body: bytes, arguments: Dict[str, List[bytes]], files: Dict[str, List[HTTPFile]], headers: HTTPHeaders = None, ) -> None: """Parses a form request body. Supports ``application/x-www-form-urlencoded`` and ``multipart/form-data``. The ``content_type`` parameter should be a string and ``body`` should be a byte string. The ``arguments`` and ``files`` parameters are dictionaries that will be updated with the parsed contents. """

    if content_type.startswith("application/x-www-form-urlencoded"):
        if headers and "Content-Encoding" in headers:
            gen_log.warning(
                "Unsupported Content-Encoding: %s", headers["Content-Encoding"]
            )
            return
        try:
            uri_arguments = parse_qs_bytes(native_str(body), keep_blank_values=True)
        except Exception as e:
            gen_log.warning("Invalid x-www-form-urlencoded body: %s", e)
            uri_arguments = {}
        for name, values in uri_arguments.items():
            if values:
                arguments.setdefault(name, []).extend(values)
    elif content_type.startswith("multipart/form-data"):
        if headers and "Content-Encoding" in headers:
            gen_log.warning(
                "Unsupported Content-Encoding: %s", headers["Content-Encoding"]
            )
            return
        try:
            fields = content_type.split(";")
            for field in fields:
                k, sep, v = field.strip().partition("=")
                if k == "boundary" and v:
                    parse_multipart_form_data(utf8(v), body, arguments, files)
                    break
            else:
                raise ValueError("multipart boundary not found")
        except Exception as e:
            gen_log.warning("Invalid multipart/form-data: %s", e)