code: def unique_ordered(data):
      
      data = np.asanyarray(data)
      order = np.sort(np.unique(data, return_index=True)[1])
      result = data[order]
      return result
docs: Returns the same as np.unique, but ordered as per the
      first occurrence of the unique value in data.
  
      Examples
      ---------
      In [1]: a = [0, 3, 3, 4, 1, 3, 0, 3, 2, 1]
  
      In [2]: np.unique(a)
      Out[2]: array([0, 1, 2, 3, 4])
  
      In [3]: trimesh.grouping.unique_ordered(a)
      Out[3]: array([0, 3, 4, 1, 2])