Set a symbol for a device

        :param str symbol: Symbol to use

def set_symbol(self, symbol):
        """
        Set a symbol for a device

        :param str symbol: Symbol to use
        """
        if symbol == 'EtherSwitch router':
            symbol = 'multilayer_switch'
        elif symbol == 'Host':
            symbol = 'computer'

        normal = ':/symbols/%s.normal.svg' % symbol
        selected = ':/symbols/%s.selected.svg' % symbol

        self.node['default_symbol'] = normal
        self.node['hover_symbol'] = selected