code: def _kernel_init():
      return _core.ElementwiseKernel(
          "X x",
          "Y y",
          "if (x == 0) { y = -1; } else { y = i; }",
          "cupyx_scipy_ndimage_label_init",
      )
  
imports: import warnings
  import numpy
  import cupy
  from cupy import _core
  from cupy import _util
label_desc: Use image node_id 4 for calling a global function with example usage: _kernel_init() and returns: _core