Log deprecation warning.

    Args:
        name (str): name of the deprecated item.
        text (str, optional): information about the deprecation.
        eos (str, optional): end of service date such as "YYYY-MM-DD".

def log_deprecated(name="", text="", eos=""):
    """
    Log deprecation warning.

    Args:
        name (str): name of the deprecated item.
        text (str, optional): information about the deprecation.
        eos (str, optional): end of service date such as "YYYY-MM-DD".
    """
    assert name or text
    if eos:
        eos = "after " + datetime(*map(int, eos.split("-"))).strftime("%d %b")
    if name:
        if eos:
            warn_msg = "%s will be deprecated %s. %s" % (name, eos, text)
        else:
            warn_msg = "%s was deprecated. %s" % (name, text)
    else:
        warn_msg = text
        if eos:
            warn_msg += " Legacy period ends %s" % eos
    logger.warn("[Deprecated] " + warn_msg)