'Add a `link` to the scheme.
Parameters
link : :class:`.SchemeLink`
An initialized link instance to add to the scheme.'

def add_link(self, link):

    check_type(link, SchemeLink)
    self.check_connect(link)
    self.__links.append(link)
    log.info(('Added    link    %r    (%r)    ->    %r    (%r)    to    scheme    %r.' % (link.source_node.title, link.source_channel.name, link.sink_node.title, link.sink_channel.name, self.title)))
    self.link_added.emit(link)
