code: def export(self, folder_path, format=None):
          
  
          if format is None:
              raise ValueError("Must export to a specific format, no format specified.")
  
          format = format.lower()
  
          if format == "trackline" or format[-4:] == "trkl":
              ex.Trackline.export(folder=folder_path, particles=self.particles, datetimes=self.datetimes)
          elif format == "shape" or format == "shapefile" or format[-3:] == "shp":
              ex.GDALShapefile.export(folder=folder_path, particles=self.particles, datetimes=self.datetimes)
          elif format == "netcdf" or format[-2:] == "nc":
              ex.NetCDF.export(folder=folder_path, particles=self.particles, datetimes=self.datetimes, summary=str(self))
          elif format == "pickle" or format[-3:] == "pkl" or format[-6:] == "pickle":
              ex.Pickle.export(folder=folder_path, particles=self.particles, datetimes=self.datetimes)
docs: General purpose export method, gets file type
              from filepath extension
  
              Valid output formats currently are:
                  Trackline: trackline or trkl or *.trkl
                  Shapefile: shapefile or shape or shp or *.shp
                  NetCDF:    netcdf or nc or *.nc