code: def test_repr_kernels(kernel):
      # Smoke-test for repr in kernels.
  
      repr(kernel)
  
imports: from inspect import signature
  import numpy
  import pytest
  from sklearn.base import clone
  from sklearn.gaussian_process.kernels import RBF, CompoundKernel, ConstantKernel, DotProduct, Exponentiation, ExpSineSquared, KernelOperator, Matern, PairwiseKernel, RationalQuadratic, WhiteKernel, _approx_fprime
  from sklearn.metrics.pairwise import PAIRWISE_KERNEL_FUNCTIONS, euclidean_distances, pairwise_kernels
  from sklearn.utils._testing import assert_allclose, assert_almost_equal, assert_array_almost_equal, assert_array_equal
label_desc: Use image node_id 16 for calling a global function with example usage: test_repr_kernels(kernel) without return types