'send method compatible with OWBaseWidget.'

def send(self, widget, channelname, value, signal_id):

    scheme = self.scheme()
    try:
        node = scheme.node_for_widget(widget)
    except KeyError:
        log.debug("Node    for    '%s'    (%s.%s)    is    not    in    the    scheme.", widget.captionTitle, type(widget).__module__, type(widget).__name__)
        return
    try:
        channel = node.output_channel(channelname)
    except ValueError:
        log.error('%r    is    not    valid    signal    name    for    %r', channelname, node.description.name)
        return
    signal_id = (widget.widget_id, channelname, signal_id)
    SignalManager.send(self, node, channel, value, signal_id)
