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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 set_default(sld, tld):
    '''
    Sets domain to use namecheap default DNS servers. Required for free
    services like Host record management, URL forwarding, email forwarding,
    dynamic DNS and other value added services.

    sld
        SLD of the domain name

    tld
        TLD of the domain name

    Returns ``True`` if the domain was successfully pointed at the default DNS
    servers.

    CLI Example:

    .. code-block:: bash

        salt 'my-minion' namecheap_domains_dns.set_default sld tld
    '''
    opts = salt.utils.namecheap.get_opts('namecheap.domains.dns.setDefault')
    opts['SLD'] = sld
    opts['TLD'] = tld
    response_xml = salt.utils.namecheap.post_request(opts)
    if response_xml is None:
        return False

    dnsresult = response_xml.getElementsByTagName('DomainDNSSetDefaultResult')[0]
    return salt.utils.namecheap.string_to_value(dnsresult.getAttribute('Updated'))