code: def sigmoid_kernel(X, Y, gamma=None, coef0=1):
      if gamma is None:
          gamma = 1.0 / X.shape[1]
  
      K = cp.dot(X, Y.T)
      K *= gamma
      K += coef0
      cp.tanh(K, K)
      return 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 3 for calling a global function with example usage: sigmoid_kernel(X, Y, gamma, coef0) and returns: K