code: def test_composite_elemwise_float16(self):
      w = theano.tensor.bvector()
      x = theano.tensor.vector(dtype="float16")
      y = theano.tensor.fvector()
  
      cz = tensor.tanh(x + tensor.cast(y, "float16"))
      o = (
          cz
          - cz**2
          + tensor.cast(x, "int16")
          + tensor.cast(x, "float32")
          + tensor.cast(w, "float16")
          - tensor.constant(np.float16(1.0))
      )
  
      theano.function([w, x, y], o, mode=mode_with_gpu)
  
      v = theano.tensor.vector(dtype="uint8")
      w = theano.tensor.vector(dtype="float16")
      x = theano.tensor.vector(dtype="float16")
      y = theano.tensor.vector(dtype="float16")
      z = theano.tensor.vector(dtype="float16")
  
      o = tensor.switch(v, tensor.mul(w, x, y), z)
      theano.function([v, w, x, y, z], o, mode=mode_with_gpu)
  
imports: from __future__ import absolute_import, print_function, division
  from copy import copy
  from unittest import TestCase
  import numpy
  import theano
  from theano import scalar, gof, tensor
  from theano.compile import DebugMode, Mode
  from theano.tests.unittest_tools import SkipTest, assert_allclose
  from theano.tensor.tests import test_elemwise
  from .config import mode_with_gpu, mode_without_gpu, test_ctx_name
  from .test_basic_ops import rand_gpuarray
  from ..elemwise import GpuElemwise, GpuDimShuffle, GpuCAReduceCuda, GpuCAReduceCPY, GpuErfinv, GpuErfcinv
  from ..dnn import GpuDnnReduction
  from ..type import GpuArrayType, get_context, gpuarray_shared_constructor
  from pygpu import ndgpuarray
label_desc: Use image node_id 1 for calling the test_float16 obj's underlying member method code with example usage: obj.test_composite_elemwise_float16() without return types