head_config.json

{
  "config": {
    "activation_function": "tanh",
    "bias": true,
    "head_type": "classification",
    "label2id": {},
    "layers": 2,
    "num_labels": 1,
    "use_pooler": false
  },
  "hidden_size": 768,
  "model_class": "BertModelWithHeads",
  "model_name": "bert-base-uncased",
  "model_type": "bert",
  "name": "glue_stsb"
}