'Remove a `node` from the scheme. All links into and out of the
`node` are also removed. If the node in not in the scheme an error
is raised.
Parameters
node : :class:`.SchemeNode`
Node instance to remove.'

def remove_node(self, node):

    check_arg((node in self.__nodes), 'Node    is    not    in    the    scheme.')
    self.__remove_node_links(node)
    self.__nodes.remove(node)
    log.info(('Removed    node    %r    from    scheme    %r.' % (node.title, self.title)))
    self.node_removed.emit(node)
    return node
