def __init__(self, graph, initial_membership=None):
if initial_membership is not None:<EOL><INDENT>initial_membership = list(initial_membership)<EOL><DEDENT>super(MutableVertexPartition, self).__init__(graph, initial_membership)<EOL>
Parameters
----------
graph
  The `ig.Graph` on which this partition is defined.

membership
  The membership vector of this partition. Membership[i] = c implies that
  node i is in community c. If None, it is initialised with a singleton
  partition community, i.e. membership[i] = i.