docstr: ...Test n_nodes attribute of Point Process
          
docstr_tok: ["...","Test","n_nodes","attribute","of","Point","Process"]
code: def test_n_nodes(self):
      """...Test n_nodes attribute of Point Process"""
      self.assertEqual(self.poisson_process.n_nodes, 3)
  
file_path: tick/tick/hawkes/simulation/tests/simu_point_process_test.py
imports: import unittest
  import numpy
  from tick.base import TimeFunction
  from tick.hawkes import SimuInhomogeneousPoisson, SimuPoissonProcess
label_desc: Use image node_id 2 for calling the Test obj's underlying member method code with example usage: obj.test_n_nodes() without return types