code: def test_find_issues_no_imbalance(self, labels, create_issue_manager):
      N = len(labels)
      labels[0] = 0
      issue_manager = create_issue_manager(labels)
      issue_manager.find_issues()
      issues, summary = issue_manager.issues, issue_manager.summary
      assert np.sum(issues["is_class_imbalance_issue"]) == 0
      assert np.all(
          issues["is_class_imbalance_issue"] == np.full(N, False)
      ), "Issue mask should be correct"
      scores = issues["class_imbalance_score"]
      expected_scores = np.ones_like(scores)
      expected_scores[labels == 1] = 0.47  # Rare class proportion
      np.testing.assert_allclose(
          scores, expected_scores, err_msg="Scores should be correct"
      )
      assert summary["issue_type"][0] == "class_imbalance"
      assert summary["score"][0] == 0.47
  
file_path: cleanlab/tests/datalab/issue_manager/test_imbalance.py
imports: import numpy
  import pytest
  from cleanlab.datalab.internal.issue_manager.imbalance import ClassImbalanceIssueManager
label_desc: Use image node_id 4 for calling the TestClassImbalanceIssueManager obj's underlying member method code with example usage: obj.test_find_issues_no_imbalance(labels, create_issue_manager) without return types