code: def test_search_frequencies():
      rng = np.random.RandomState(0)
  
      t = np.arange(0, 1e1, 0.01)
      f = 1
      w = 2 * np.pi * np.array(f)
      y = np.sin(w * t)
  
      dy = 0.01
      y += dy * rng.randn(len(y))
  
      omegas, power = search_frequencies(t, y, dy)
      omax = omegas[power == max(power)]
  
      assert_almost_equal(w, omax, decimal=3)
  
imports: import numpy
  from numpy.testing import assert_almost_equal
  from astroML.time_series import search_frequencies
label_desc: Use image node_id 1 for calling a global function with example usage: test_search_frequencies() without return types