code: def _L(self, parm):
           
  
          return np.linalg.cholesky(self.kernel.K(parm) + np.identity(self.X().shape[1])*parm[0])
docs: Creates cholesky decomposition of covariance matrix
  
          Parameters
          ----------
          parm : np.array
              Contains transformed latent variables
  
          Returns
          ----------
          The cholesky decomposition (L) of K