code: def test_t_contrast_add(set_up_glm, rng):
      labels, results, q = set_up_glm(rng, "ols")
      c1, c2 = np.eye(q)[0], np.eye(q)[1]
  
      con = compute_contrast(labels, results, c1) + compute_contrast(
          labels, results, c2
      )
  
      z_vals = con.z_score()
  
      assert_almost_equal(z_vals.mean(), 0, 0)
      assert_almost_equal(z_vals.std(), 1, 0)
  
imports: import numpy
  import pytest
  import scipy.stats
  from numpy.testing import assert_almost_equal
  from sklearn.datasets import make_regression
  from sklearn.linear_model import LinearRegression
  from nilearn.glm.contrasts import Contrast, _compute_fixed_effects_params, compute_contrast, compute_fixed_effect_contrast, expression_to_contrast_vector
  from nilearn.glm.first_level import run_glm
label_desc: Use image node_id 7 for calling a global function with example usage: test_t_contrast_add(set_up_glm, rng) without return types