class_docstr: convert numpy array to list for JSON serialize
code: def default(self, obj):
      if isinstance(obj, np.integer):
          return int(obj)
      elif isinstance(obj, np.floating):
          return float(obj)
      elif isinstance(obj, np.ndarray):
          return obj.tolist()
      return json.JSONEncoder.default(self, obj)
  
file_path: BigDL/python/chronos/src/bigdl/chronos/autots/deprecated/feature/utils.py
imports: import json
  import os
  import numpy
label_desc: Use image node_id 1 for calling the NumpyEncoder obj's underlying member method code with example usage: obj.default(obj) and returns: json, int, float, obj