docs: def get_partition_trees(self, p):
          """
          Return the trees associated with a partition, p
          """
          trees = []
          for grp in p.get_membership():
              try:
                  result = self.get_group_result(grp)
                  trees.append(result['ml_tree'])
              except ValueError:
                  trees.append(None)
                  logger.error('No tree found for group {}'.format(grp))
          return trees