class_docstr: Collect all tasks into a single result.csv file
class_docstr_tok: ["Collect","all","tasks","into","a","single","result.csv","file"]
code: def run(self):
      results = []
  
      for input_file in self._get_input_targets("result.json"):
          with input_file.open("r") as f:
              results.append(json.load(f))
  
      df = pd.DataFrame(results)
  
      with self._get_output_target("results.csv").open("w") as f:
          df.to_csv(f)
  
imports: import json
  from time import time
  import b2luigi
  import numpy
  import pandas
  from tsfresh.feature_extraction import ComprehensiveFCParameters, MinimalFCParameters, extract_features
label_desc: Use image node_id 4 for calling the CombinerTask obj's underlying member method code with example usage: obj.run() without return types