code: def unique_sets(sets, return_inverse=False):
      """Remove duplicate sets.
  
      Parameters
      ----------
      sets : array (N, k)
          N sets of size k.
      return_inverse : bool
          If True, also returns the indices of unique_sets that can be used
          to reconstruct `sets` (the original ordering of each set may not be
          preserved).
  
      Returns
      -------
      unique_sets : array
          Unique sets.
      inverse : array (N,)
          The indices to reconstruct `sets` from `unique_sets`.
  
      """
      sets = np.sort(sets, 1)
      order = np.lexsort(sets.T)
      sets = sets[order]
      flag = np.ones(len(sets), "bool")
      flag[1:] = (sets[1:] != sets[:-1]).any(-1)
      uniqsets = sets[flag]
      if return_inverse:
          inverse = np.empty_like(order)
          inverse[order] = np.arange(len(order))
          index = flag.cumsum() - 1
          return uniqsets, index[inverse]
      else:
          return uniqsets
  
imports: import numpy
  import warnings
  from scipy import optimize
  from dipy.core.geometry import cart2sphere, sphere2cart, vector_norm
  from dipy.core.onetime import auto_attr
  from dipy.reconst.recspeed import remove_similar_vertices
label_desc: Use image node_id 5 for calling a global function with example usage: unique_sets(sets, return_inverse) and returns: uniqsets,  index, uniqsets