code: def usage(self):
          '''return the samtools usage information for this command'''
          retval, stderr, stdout = _pysam_dispatch(
              self.collection,
              self.dispatch,
              is_usage=True,
              catch_stdout=True)
          # some tools write usage to stderr, such as mpileup
          if stderr:
              return stderr
          else:
              return stdouf usage(self):
          '''return the samtools usage information for this command'''
          retval, stderr, stdout = _pysam_dispatch(
              self.collection,
              self.dispatch,
              is_usage=True,
              catch_stdout=True)
          # some tools write usage to stderr, such as mpileup
          if stderr:
              return stderr
          else:
              return stdout
docs: return the samtools usage information for this command