docstr: Return the earliest timestamp in the time series.
docstr_tok: ["Return","the","earliest","timestamp","in","the","time","series","."]
code: def start(self):
      """
      Return the earliest timestamp in the time series.
      """
      return min(self.timestamps) if self.timestamps else None
  
imports: import numpy
label_desc: Use image node_id 2 for calling the TimeSeries obj's underlying member method code with example usage: obj.start() and returns: unknown