code: def infer_feature_characteristics(self, ts):
      self.num_feat_static_real = (
          0
          if ("feat_static_real" not in ts)
          or (self.use_feat_static_real is False)
          else len(ts["feat_static_real"])
      )
      self.num_feat_static_cat = (
          0
          if ("feat_static_cat" not in ts)
          else len(ts["feat_static_cat"])
      )
      self.num_past_feat_dynamic_real = (
          0
          if ("past_feat_dynamic_real" not in ts)
          or (self.use_past_feat_dynamic_real is False)
          else len(ts["past_feat_dynamic_real"])
      )
      self.num_feat_dynamic_real = (
          0
          if ("feat_dynamic_real" not in ts)
          or (self.use_feat_dynamic_real is False)
          else len(ts["feat_dynamic_real"])
      )
      self.num_feat_dynamic_cat = (
          0
          if ("feat_dynamic_cat" not in ts)
          or (self.use_feat_dynamic_cat is False)
          else len(ts["feat_dynamic_real"])
      )
  
imports: import concurrent.futures
  import logging
  from enum import Enum
  from itertools import chain, starmap
  from typing import Dict, List, Tuple, Union, Optional, Sequence
  import numpy
  from gluonts.core.component import validated
label_desc: Use image node_id 6 for calling the PreprocessOnlyLagFeatures obj's underlying member method code with example usage: obj.infer_feature_characteristics(ts) without return types