code: def test__zseries_to_cseries(self):
      for i in range(5):
          inp = np.array([0.5] * i + [2] + [0.5] * i, np.double)
          tgt = np.array([2] + [1] * i, np.double)
          res = cheb._zseries_to_cseries(inp)
          assert_equal(res, tgt)
  
imports: from functools import reduce
  import numpy
  import numpy.polynomial.chebyshev
  from numpy.polynomial.polynomial import polyval
  from numpy.testing import assert_almost_equal, assert_raises, assert_equal, assert_
label_desc: Use image node_id 2 for calling the TestPrivate obj's underlying member method code with example usage: obj.test__zseries_to_cseries() without return types