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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 _find_assignment(arg_token):
 """ Find the first non-escaped assignment in the given argument token. Returns -1 if no assignment was found. :param arg_token: The argument token :return: The index of the first assignment, or -1 """

    idx = arg_token.find("=")
    while idx != -1:
        if idx != 0 and arg_token[idx - 1] != "\\":
            # No escape character
            return idx

        idx = arg_token.find("=", idx + 1)

    # No assignment found
    return -1