code: def __init__(self, nan_str="null", **kwargs):
      super(SafeFallbackEncoder, self).__init__(**kwargs)
      self.nan_str = nan_str
  
imports: import json
  import numbers
  import numpy
label_desc: Use image node_id 1 to create a new SafeFallbackEncoder object from inherited base classes: json with example: obj = SafeFallbackEncoder(nan_str)