code: def chi2_kernel(X, Y, gamma=1.0):
      K = additive_chi2_kernel(X, Y)
      K *= gamma
      return cp.exp(K, K)
  
file_path: cuml/python/cuml/metrics/pairwise_kernels.py
imports: from cuml.internals.input_utils import input_to_cupy_array
  from cuml.metrics import pairwise_distances
  import cuml.internals
  from cuml.internals.safe_imports import cpu_only_import
  from cuml.internals.safe_imports import gpu_only_import
  import inspect
  from cuml.internals.safe_imports import gpu_only_import_from
label_desc: Use image node_id 9 for calling a global function with example usage: chi2_kernel(X, Y, gamma) and returns: cp