new_contents: import numpy as np
  from numpy.testing import assert_allclose
  from menpo.shape import PointCloud, mean_pointcloud, TriMesh
  
  
  def test_mean_pointcloud():
      points = np.array([[1, 2, 3],
                         [1, 1, 1]])
      pcs = [PointCloud(points), PointCloud(points + 2)]
      mean_pc = mean_pointcloud(pcs)
      assert isinstance(mean_pc, PointCloud)
      assert_allclose(mean_pc.points, points + 1)
  
  
  def test_mean_pointcloud_type():
      points = np.array([[1, 2, 3],
                         [1, 1, 1]])
      trilist = np.array([0, 1, 2])
      pcs = [TriMesh(points, trilist), TriMesh(points + 2, trilist)]
      mean_pc = mean_pointcloud(pcs)
      assert isinstance(mean_pc, TriMesh)
      assert_allclose(mean_pc.points, points + 1)
  
subject: Add tests for mean_pointcloud