How to use the altgraph.Graph.Graph function in altgraph

def as_graph(processes, settings):
    """
    Return a graph from a list of process objects.
    """
    logger.info('Building graph ...')
    from altgraph.Graph import Graph
    graph = Graph()
##############################################################################
# TODO: CRITICAL to avoid cycles in the graph and ensure this is DAG
# directed acyclic graph: http://en.wikipedia.org/wiki/Directed_acyclic_graph
# we should take timing into consideration:
# the first read to a given path can only happen after the last write has been
# completed, IFF there are writes that precede a given read
# therefore a path may appear several times in the graph based on the
# read/writes
# this applies to actual files, but be may not to pipes or sockets
##############################################################################
    for proc in processes:
        if proc.is_empty():
            continue
        # FIXME: handle forks
        # if not settings.forks and proc.is_pure_forker():
        #     continue

def __init__(self, graph=None, debug=0):
        if graph is None:
            graph = Graph()
        self.graphident = self
        self.graph = graph
        self.debug = debug
        self.indent = 0
        graph.add_node(self, None)

def __init__(self, graph=None, debug=0):
        if graph is None:
            graph = Graph()
        self.graphident = self
        self.graph = graph
        self.debug = debug
        self.indent = 0
        graph.add_node(self, None)