old_contents: import numpy as np
  
  
  def test_grid_x(initialized_bmi, gid):
      gtype = initialized_bmi.get_grid_type(gid)
      if gtype == "unstructured":
          ndim = bmi.get_grid_rank(gid)
          size = bmi.get_grid_size(gid)
  
          x = np.full(size, np.nan)
          assert x is bmi.get_grid_x(gid, x)
          assert np.all(~np.isnan(arr))
  
new_contents: import numpy as np
  
  
  def test_grid_x(initialized_bmi, gid):
      gtype = initialized_bmi.get_grid_type(gid)
      if gtype == "unstructured":
          size = initialized_bmi.get_grid_size(gid)
  
          x = np.full(size, np.nan)
          assert x is initialized_bmi.get_grid_x(gid, x)
          assert np.all(~np.isnan(x))
  
subject: Fix undefined variables.