code: def _unique_multiclass(y):
      if hasattr(y, "__array__"):
          return np.unique(np.asarray(y))
      else:
          return set(y)
  
imports: from __future__ import division
  from collections import Sequence
  from itertools import chain
  from scipy.sparse import issparse
  from scipy.sparse.base import spmatrix
  from scipy.sparse import dok_matrix
  from scipy.sparse import lil_matrix
  import numpy
  from ..externals.six import string_types
  from .validation import check_array
  from ..utils.fixes import bincount
  from ..utils.fixes import array_equal
label_desc: Use image node_id 1 for calling a global function with example usage: _unique_multiclass(y) and returns: np, set