code: def estimation_error(estimated, original):
      return (
          np.linalg.norm(original - estimated) ** 2
          / np.linalg.norm(original) ** 2
      )
  
imports: import unittest
  import numpy
  from tick.base.inference import InferenceTest
  from tick.hawkes import SimuHawkesExpKernels
  from tick.hawkes.inference import HawkesExpKern
  from tick.hawkes.model.model_hawkes_expkern_leastsq import ModelHawkesExpKernLeastSq
  from tick.hawkes.model.model_hawkes_expkern_loglik import ModelHawkesExpKernLogLik
  from tick.prox import ProxNuclear
  from tick.prox import ProxPositive, ProxL1, ProxL2Sq, ProxElasticNet
  from tick.solver import AGD, GD, BFGS, SGD, SVRG
label_desc: Use image node_id 3 for calling the Test obj's underlying member method code with example usage: obj.estimation_error(estimated, original) and returns: unknown