code: def test_delete_head(self):
      model = AutoAdapterModel.from_config(self.config())
      model.eval()
  
      name = "test_head"
      self.add_head(model, name)
      self.assertTrue(name in model.heads)
      self.assertTrue(name in model.config.prediction_heads)
      self.assertEqual(name, model.active_head)
  
      model.delete_head(name)
      self.assertFalse(name in model.heads)
      self.assertFalse(name in model.config.prediction_heads)
      self.assertNotEqual(name, model.active_head)
  
imports: import os
  import tempfile
  import torch
  import adapters
  from adapters import ADAPTER_MODEL_MAPPING, AdapterSetup, AutoAdapterModel
  from adapters.composition import BatchSplit, Stack
  from transformers import AutoModelForSequenceClassification
  from transformers.testing_utils import require_torch, torch_device
  from .methods import create_twin_models
label_desc: Use image node_id 12 for calling the PredictionHeadModelTestMixin obj's underlying member method code with example usage: obj.test_delete_head() without return types