class_docstr: NumericalStats contains following basic information:
      - _total_count: total count of values
      - _nan_count: total count of nan values
      - _min: minimum of all values
      - _max: maximum of all values
      - _mean: mean of the values
      - _median: median of the values
      - _sd: standard deviation of the values
      - _histogram: a histogram of value distribution represented by a list of (x_left, x_right, count)
      - _kde: a kernel density estimation curve represented by a list of points
class_docstr_tok: ["NumericalStats","contains","following","basic","information",":","-","_total_count",":","total","count","of","values","-","_nan_count",":","total","count","of","nan","values","-","_min",":","minimum","of","all","values","-","_max",":","maximum","of","all","values","-","_mean",":","mean","of","the","values","-","_median",":","median","of","the","values","-","_sd",":","standard","deviation","of","the","values","-","_histogram",":","a","histogram","of","value","distribution","represented","by","a","list","of","(","x_left",",","x_right",",","count",")","-","_kde",":","a","kernel","density","estimation","curve","represented","by","a","list","of","points"]
code: def nan_count(self):
      return self._nan_count
  
imports: from typing import Dict, List, Tuple, Optional, Union
  from xai.data.abstract_stats import AbstractStats
  from xai.data.constants import STATSKEY
  from xai.data.exceptions import InvalidTypeError, InvalidSizeError
label_desc: Use image node_id 12 for calling the NumericalStats obj's underlying member method code with example usage: obj.nan_count() and returns: self