new_contents: import numpy as np
  import scarab
  from nose.tools import *
  
  from common.utils import *
  
  
  def test_binary():
      a = binary(1, size=5)
      assert_true(np.all(a == [0, 0, 0, 0, 1]))
      a = binary(2, size=3)
      assert_true(np.all(a == [0, 1, 0]))
  
  def test_encrypt_index():
      pk, sk = scarab.generate_pair()
      c = encrypt_index(pk, 1, 5)
      assert_true(len(c) == 5)
subject: Add utility tests