code: def _add_eltwise_fusion_configs(
      configs,
      root_module,
      root_op,
      post_module,
      post_op,
      dtype_configs,
      fuser_method,
      fused_module,
      observation_type,
      ref_quant_module,
  ):
      # 1 base module + op module fusion config
      configs.append(
          BackendPatternConfig((root_module, post_module))
          .set_dtype_configs(dtype_configs)  # noqa: E131
          .set_fuser_method(fuser_method)
          .set_fused_module(fused_module)
      )
      # base module + functional post op
      configs.append(
          BackendPatternConfig((root_module, post_op))
          .set_dtype_configs(dtype_configs)  # noqa: E131
          .set_fuser_method(fuser_method)
          .set_fused_module(fused_module)
      )
  
      # 2 fused module configs
      configs.append(
          BackendPatternConfig(fused_module)
          .set_observation_type(observation_type)  # noqa: E131
          .set_dtype_configs(dtype_configs)
          .set_root_module(root_module)
          .set_reference_quantized_module(ref_quant_module)
      )
  
      # 3 functional base op + post op configs
      configs.append(
          BackendPatternConfig((root_op, post_module))
          .set_observation_type(observation_type)  # noqa: E131
          .set_dtype_configs(dtype_configs)
      )
      configs.append(
          BackendPatternConfig((root_op, post_op))
          .set_observation_type(observation_type)  # noqa: E131
          .set_dtype_configs(dtype_configs)
      )
  
imports: import torch
  import torch.nn
  import torch.ao.nn.intrinsic
  import torch.nn.functional
  import torch.ao.nn.quantized.reference
  from ._common_operator_config_utils import _get_conv_configs, _get_linear_configs, _get_binary_op_configs, _get_bn_configs, _get_cat_config, _get_default_op_configs, _get_embedding_op_configs, _get_fixed_qparams_op_configs, _get_ln_configs, _get_rnn_op_configs, _get_share_qparams_op_configs
  from .backend_config import BackendPatternConfig, BackendConfig, DTypeConfig, ObservationType
  from ..fuser_method_mappings import _sequential_wrapper2
  import operator
  from torch.ao.quantization.utils import MatchAllNode
  import itertools
label_desc: Use image node_id 26 for calling a global function with example usage: _add_eltwise_fusion_configs(configs, root_module, root_op, post_module, post_op, dtype_configs, fuser_method, fused_module, observation_type, ref_quant_module) without return types