code: def test_hash_format_sparse(self):
      h = self.pdp.hash_vector(scipy.sparse.rand(10, 1, density=0.6))
      self.assertEqual(len(h), 1)
      self.assertEqual(type(h[0]), type(""))
  
imports: import numpy
  import scipy
  import unittest
  from nearpy.hashes import RandomBinaryProjections, RandomDiscretizedProjections, PCABinaryProjections, PCADiscretizedProjections
label_desc: Use image node_id 4 for calling the TestPCADiscretizedProjections obj's underlying member method code with example usage: obj.test_hash_format_sparse() without return types