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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 list_platforms(server_url):
    '''
    To list all ASAM platforms present on the Novell Fan-Out Driver

    CLI Example:

    .. code-block:: bash

        salt-run asam.list_platforms prov1.domain.com
    '''
    config = _get_asam_configuration(server_url)
    if not config:
        return False

    url = config['platform_config_url']

    data = {
        'manual': 'false',
    }

    auth = (
        config['username'],
        config['password']
    )

    try:
        html_content = _make_post_request(url, data, auth, verify=False)
    except Exception as exc:
        err_msg = "Failed to look up existing platforms"
        log.error('%s:\n%s', err_msg, exc)
        return {server_url: err_msg}

    parser = _parse_html_content(html_content)
    platform_list = _get_platforms(parser.data)

    if platform_list:
        return {server_url: platform_list}
    else:
        return {server_url: "No existing platforms found"}