docstr: return         self.kernel_relu._single_layer_M(x1norm,x1sum)
docstr_tok: ["return","self.kernel_relu._single_layer_M","(","x1norm",",","x1sum",")"]
code: def _single_layer_M(self, x1norm, x1sum):
      """
          return \
          self.kernel_relu._single_layer_M(x1norm,x1sum)
          """
      return np.zeros_like(x1sum)
  
file_path: elu-gelu-kernels/code/kernels/nn_kernel_elu.py
imports: import numpy
  from scipy.stats import multivariate_normal
  from scipy.stats import norm
  from scipy.special import erf
  import GPy
  import abc
  from .nn_kernel import NNKernel
  from .nn_kernel_relu import NNKernelRelu
label_desc: Use image node_id 6 for calling the NNKernelElu obj's underlying member method code with example usage: obj._single_layer_M(x1norm, x1sum) and returns: np