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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 server_exists(s_name, ip=None, s_state=None, **connection_args):
    '''
    Checks if a server exists

    CLI Example:

    .. code-block:: bash

        salt '*' netscaler.server_exists 'serverName'
    '''
    server = _server_get(s_name, **connection_args)
    if server is None:
        return False
    if ip is not None and ip != server.get_ipaddress():
        return False
    if s_state is not None and s_state.upper() != server.get_state():
        return False
    return True