class_docstr: HDD results.
class_docstr_tok: ["HDD","results","."]
docstr: Save results object as master file.
docstr_tok: ["Save","results","object","as","master","file","."]
code: def save(self):
      """Save results object as master file."""
      file = os.path.join(self.path, "results.pickle")
  
      # if file does not exist already, create a new one
      if not os.path.isfile(file):
          dump(self, file)
  
      # if file already exists, update file adding new datasets,
      # strategies and/or cv_folds
      else:
          results = load(file)
          self.strategy_names = list(
              set(self.strategy_names + results.strategy_names)
          )
          self.dataset_names = list(
              set(self.dataset_names + results.dataset_names)
          )
          dump(self, file)
  
imports: import os
  from abc import ABC, abstractmethod
  from warnings import warn
  import numpy
  from joblib import dump, load
label_desc: Use image node_id 3 for calling the HDDBaseResults obj's underlying member method code with example usage: obj.save() without return types