def build(self, tree):
self.diagram = Diagram()
self.diagram = self.instantiate(self.diagram, None, tree)
self.update_node_order()
self.update_edge_order()
self.update_altblock_ylevel()
self.diagram.colwidth = len(self.diagram.nodes)
self.diagram.colheight = len(self.diagram.edges) + 1
for sep in self.diagram.separators:
self.diagram.edges.remove(sep)
if self.diagram.activation != 'none':
self.create_activities()
if self.diagram.autonumber:
self.update_label_numbered()
return self.diagram
