def get_nodes(self):
nodes = []<EOL>for age, level in enumerate(self.nodes):<EOL><INDENT>nodes.append([])<EOL>for node in level:<EOL><INDENT>nodes[age].append(node.get_tuple())<EOL><DEDENT><DEDENT>return nodes<EOL>
Get the tree nodes as list.

        Returns:
            list: A 2d-list holding the grown nodes coordinates as tupel for every age.
                Example:
                [
                [(10, 40)],
                [(20, 80), (100, 30)],
                [(100, 90), (120, 40), ...],
                ...
                ]