code: def handle_missing(self, fltr):
      if self.cfg is None or not self.cfg.get("missing", False):
          return fltr
      return {
          "missing": True,
          "meta": {
              "column": self.column,
              "classification": self.classification,
              "type": self.cfg["type"],
          },
          "query": "{col}.isnull()".format(
              col=build_col_key(self.column)
          ),
      }
  
imports: import json
  import numpy
  import pandas
  import dtale.global_state
  from dtale.utils import classify_type, find_dtype, format_data, make_list
  from dtale.query import build_col_key
label_desc: Use image node_id 2 for calling the MissingFilter obj's underlying member method code with example usage: obj.handle_missing(fltr) and returns: dict, fltr