code: def test_none_prec_recall_scores_binary(self):
      # Arrange
      y = turicreate.SArray([0, 1])
      yhat = turicreate.SArray([0, 0])
  
      # Act
      pr = turicreate.toolkits.evaluation.precision(y, yhat)
      rec = turicreate.toolkits.evaluation.recall(y, yhat)
      f1 = turicreate.toolkits.evaluation.f1_score(y, yhat)
      fbeta = turicreate.toolkits.evaluation.fbeta_score(
          y, yhat, beta=2.0
      )
  
      # Assert
      self.assertEqual(pr, None)
      self.assertEqual(rec, 0.0)
      self.assertEqual(f1, 0.0)
      self.assertEqual(fbeta, 0.0)
  
      # Arrange
      y = turicreate.SArray([0, 0])
      yhat = turicreate.SArray([0, 1])
  
      # Act
      pr = turicreate.toolkits.evaluation.precision(y, yhat)
      rec = turicreate.toolkits.evaluation.recall(y, yhat)
      f1 = turicreate.toolkits.evaluation.f1_score(y, yhat)
      fbeta = turicreate.toolkits.evaluation.fbeta_score(
          y, yhat, beta=2.0
      )
  
      # Assert
      self.assertEqual(pr, 0.0)
      self.assertEqual(rec, None)
      self.assertEqual(f1, 0.0)
      self.assertEqual(fbeta, 0.0)
  
      # Arrange
      y = turicreate.SArray(["0", "1"])
      yhat = turicreate.SArray(["0", "0"])
  
      # Act
      pr = turicreate.toolkits.evaluation.precision(y, yhat)
      rec = turicreate.toolkits.evaluation.recall(y, yhat)
      f1 = turicreate.toolkits.evaluation.f1_score(y, yhat)
      fbeta = turicreate.toolkits.evaluation.fbeta_score(
          y, yhat, beta=2.0
      )
  
      # Assert
      self.assertEqual(pr, None)
      self.assertEqual(rec, 0.0)
      self.assertEqual(f1, 0.0)
      self.assertEqual(fbeta, 0.0)
  
      # Arrange
      y = turicreate.SArray(["0", "0"])
      yhat = turicreate.SArray(["0", "1"])
  
      # Act
      pr = turicreate.toolkits.evaluation.precision(y, yhat)
      rec = turicreate.toolkits.evaluation.recall(y, yhat)
      f1 = turicreate.toolkits.evaluation.f1_score(y, yhat)
      fbeta = turicreate.toolkits.evaluation.fbeta_score(
          y, yhat, beta=2.0
      )
  
      # Assert
      self.assertEqual(pr, 0.0)
      self.assertEqual(rec, None)
      self.assertEqual(f1, 0.0)
      self.assertEqual(fbeta, 0.0)
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import unittest
  import turicreate
  from turicreate.toolkits._main import ToolkitError
  import math
  from numpy import inf
  import numpy
label_desc: Use image node_id 7 for calling the MetricsTest obj's underlying member method code with example usage: obj.test_none_prec_recall_scores_binary() without return types