code: def test_float16_upcast(self, xp, scp):
      # float16 must be upcast to float64
      x = scp.signal.decimate(xp.ones(100, dtype=xp.float16), 10)
      return x
  
imports: import cupy
  from cupy import testing
  import cupyx.scipy.signal
  import cupyx.scipy.signal.windows
  import numpy
  import pytest
  from math import gcd
label_desc: Use image node_id 12 for calling the TestDecimate obj's underlying member method code with example usage: obj.test_float16_upcast(xp, scp) and returns: x