code: def test_single_prediction():
      # Given
      input_target_values = [100]
      input_quantile_values = [[90.0]]
      input_quantile_levels = [0.9]
      expected_output = 9.0
  
      # When
      observed_output = pinball_loss(
          input_target_values,
          input_quantile_values,
          input_quantile_levels,
      )
  
      # Then
      assert np.isclose(expected_output, observed_output)
  
file_path: autogluon/core/tests/unittests/metrics/test_quantile_metrics.py
imports: import numpy
  import pytest
  from autogluon.core.metrics.quantile_metrics import pinball_loss
label_desc: Use image node_id 4 for calling a global function with example usage: test_single_prediction() without return types