def __init__(self, graph, initial_membership=None, node_sizes=None):
if initial_membership is not None:<EOL><INDENT>initial_membership = list(initial_membership)<EOL><DEDENT>super(SignificanceVertexPartition, self).__init__(graph, initial_membership)<EOL>pygraph_t = _get_py_capsule(graph)<EOL>self._partition = _c_louvain._new_SignificanceVertexPartition(pygraph_t, initial_membership)<EOL>self._update_internal_membership()<EOL>
Parameters
----------
graph : :class:`ig.Graph`
  Graph to define the partition on.

initial_membership : list of int
  Initial membership for the partition. If :obj:`None` then defaults to a
  singleton partition.

node_sizes : list of int, or vertex attribute
  Sizes of nodes are necessary to know the size of communities in aggregate
  graphs. Usually this is set to 1 for all nodes, but in specific cases
  this could be changed.