code: def unique(segments, digits=5):
      
      segments = np.asanyarray(segments, dtype=np.float64)
  
      # find segments as unique indexes so we can find duplicates
      inverse = grouping.unique_rows(
          segments.reshape((-1, segments.shape[2])),
          digits=digits)[1].reshape((-1, 2))
  
      # make sure rows are sorted
      inverse.sort(axis=1)
      # find rows that occur once
      index = grouping.unique_rows(inverse)
      # apply the unique mask
      unique = segments[index[0]]
  
      return unique
docs: Find unique line segments.
  
      Parameters
      ------------
      segments : (n, 2, (2|3)) float
        Line segments in space
      digits : int
        How many digits to consider when merging vertices
  
      Returns
      -----------
      unique : (m, 2, (2|3)) float
        Segments with duplicates merged