code: def test_triangulation_init():
      x = [-1, 0, 1, 0]
      y = [0, -1, 0, 1]
      with pytest.raises(
          ValueError, match="x and y must be equal-length"
      ):
          mtri.Triangulation(x, [1, 2])
      with pytest.raises(
          ValueError,
          match=r"triangles must be a \(N, 3\) int array, but found shape "
          r"\(3,\)",
      ):
          mtri.Triangulation(x, y, [0, 1, 2])
      with pytest.raises(
          ValueError,
          match=r"triangles must be a \(N, 3\) int array, not 'other'",
      ):
          mtri.Triangulation(x, y, "other")
      with pytest.raises(ValueError, match="found value 99"):
          mtri.Triangulation(x, y, [[0, 1, 99]])
      with pytest.raises(ValueError, match="found value -1"):
          mtri.Triangulation(x, y, [[0, 1, -1]])
  
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 2 for calling a global function with example usage: test_triangulation_init() without return types