code: def test_merge_duplicate_points():
      global t
      pts = np.array(
          [
              [0, 0],
              [1, 1],
              [0.1, 0.7],
              [2, 3],
              [0, 0],
              [0.1, 0.7],
              [5, 6],
          ]
      )
      edges = np.array(
          [
              [0, 6],
              [1, 5],
              [2, 4],
              [3, 6],
              [4, 5],
          ]
      )
  
      t = T(pts, edges)
      t._merge_duplicate_points()
  
      pts = np.array(
          [
              [0, 0],
              [1, 1],
              [0.1, 0.7],
              [2, 3],
              [5, 6],
          ]
      )
      edges = np.array(
          [
              [0, 4],
              [1, 2],
              [2, 0],
              [3, 4],
              [0, 2],
          ]
      )
      assert np.allclose(t.pts, pts)
      assert np.all(t.edges == edges)
  
file_path: vispy/vispy/geometry/tests/test_triangulation.py
imports: import sys
  from unittest import SkipTest
  import numpy
  from numpy.testing import assert_array_almost_equal
  from vispy.testing import run_tests_if_main
  from vispy.geometry.triangulation import Triangulation
label_desc: Use image node_id 4 for calling a global function with example usage: test_merge_duplicate_points() without return types