class_docstr: Same as OutputLogger, but also requires the original activation
  in order to calculate the comparison at calibration time
class_docstr_tok: ["Same","as","OutputLogger",",","but","also","requires","the","original","activation","in","order","to","calculate","the","comparison","at","calibration","time"]
code: def __init__(self, *args, **kwargs):
      super().__init__(*args, **kwargs)
      # TODO(future PR): make the comparison function configurable
      self.comparison_fn = torch.ao.ns.fx.utils.compute_sqnr
      self.comparison_fn_name = "sqnr"
      # precalculated comparisons of logger output versus reference
      self.comparisons = []
  
imports: import collections
  import torch
  import torch.nn
  import torch.ao.quantization.quantize_fx
  from torch.fx import GraphModule
  from torch.fx.graph import Node
  from torch.ao.ns.fx.mappings import get_base_name_to_sets_of_related_ops
  from torch.ao.ns.fx.graph_matcher import get_matching_subgraph_pairs, get_type_a_related_to_b
  from .fx.weight_utils import extract_weight_from_node
  from .fx.graph_passes import add_loggers_to_model, create_a_shadows_b
  from .fx.utils import rekey_logger_info_on_node_name_of_model, maybe_add_missing_fqns, get_target_type_str
  from .fx.ns_types import NSSingleResultValuesType, NSResultsType, NSNodeTargetType
  from torch.ao.quantization.backend_config.utils import get_fusion_pattern_to_root_node_getter
  from torch.ao.quantization.backend_config import BackendConfig
  from torch.ao.quantization.fx.match_utils import _find_matches
  from torch.ao.quantization.fx.graph_module import _get_observed_graph_module_attr
  from torch.ao.quantization.fx.qconfig_mapping_utils import _generate_node_name_to_qconfig
  from torch.ao.quantization.fx.quantize_handler import _get_pattern_to_quantize_handlers
  from torch.ao.quantization.qconfig import QConfigAny
  from torch.ao.quantization import QConfigMapping
  from torch.ao.ns.fx.n_shadows_utils import OutputProp, _get_dedup_subgraphs, SHADOW_WRAPPER_NODE_NAME_PREFIX, group_results_by_subgraph, create_results_comparison, print_n_shadows_summary, create_n_transformed_and_logged_copies_of_subgraph, create_add_loggers_graph, extract_weight_comparison
  from torch.ao.ns.fx.qconfig_multi_mapping import QConfigMultiMapping
  from typing import Dict, Tuple, Callable, List, Optional, Set, Any, Type
label_desc: Use image node_id 1 to create a new OutputComparisonLogger object from inherited base classes: OutputLogger with example: obj = OutputComparisonLogger()