code: def test_fista_regression(bin_dense_train_data):
      X, y = bin_dense_train_data
      reg = FistaRegressor(max_iter=100, verbose=0)
      reg.fit(X, y)
      y_pred = np.sign(reg.predict(X))
      np.testing.assert_almost_equal(np.mean(y == y_pred), 0.985)
  
imports: import numpy
  import pytest
  from scipy.linalg import svd, diagsvd
  from lightning.classification import FistaClassifier
  from lightning.regression import FistaRegressor
  from lightning.impl.penalty import project_simplex, L1Penalty
label_desc: Use image node_id 13 for calling a global function with example usage: test_fista_regression(bin_dense_train_data) without return types