code: def meshgrid_triangles(n):
      """
      Return (2*(N-1)**2, 3) array of triangles to mesh (N, N)-point np.meshgrid.
      """
      tri = []
      for i in range(n - 1):
          for j in range(n - 1):
              a = i + j * n
              b = (i + 1) + j * n
              c = i + (j + 1) * n
              d = (i + 1) + (j + 1) * n
              tri += [[a, b, d], [a, d, c]]
      return np.array(tri, dtype=np.int32)
  
imports: import numpy
  from numpy.testing import assert_array_equal, assert_array_almost_equal, assert_array_less
  import numpy.ma.testutils
  import pytest
  import matplotlib
  import matplotlib.pyplot
  import matplotlib.tri
  from matplotlib.path import Path
  from matplotlib.testing.decorators import image_comparison, check_figures_equal
label_desc: Use image node_id 26 for calling a global function with example usage: meshgrid_triangles(n) and returns: np