code: def _get_backend_kernel(dtype, grid, block, k_type):
      kernel = _cupy_kernel_cache[(dtype, k_type)]
      if kernel:
          return _cupy_channelizer_wrapper(grid, block, kernel)
      else:
          raise ValueError(
              "Kernel {} not found in _cupy_kernel_cache".format(k_type)
          )
  
      raise NotImplementedError(
          "No kernel found for datatype {}".format(dtype)
      )
  
file_path: cusignal/python/cusignal/filtering/_channelizer_cuda.py
imports: from ..utils._caches import _cupy_kernel_cache
  from ..utils.helper_tools import _get_function, _get_numSM, _print_atts
label_desc: Use image node_id 2 for calling a global function with example usage: _get_backend_kernel(dtype, grid, block, k_type) and returns: _cupy_channelizer_wrapper