code: def from_argparse(cls, opts):
          
          return cls(opts.pn_order, opts.f_low, opts.f_upper, opts.delta_f,\
                     f0=opts.f0, write_metric=opts.write_metric)
docs: Initialize an instance of the metricParameters class from an
          argparse.OptionParser instance. This assumes that
          insert_metric_calculation_options
          and
          verify_metric_calculation_options
          have already been called before initializing the class.