def install_pip(self, package, save=True, save_dev=False):
        """Installs a pip package.

        :param save: if `True`, pins the package to the Hydrogen requirements
            YAML file.
        :param save_dev: if `True`, pins the package as a development
            dependency to the Hydrogen requirements YAML file.
        :param return: a **single** :class:`Requirement` object, representing
            the installed version of the given package.
        """
        requirement = Requirement.coerce(package)
        click.echo("pip install " + requirement.package)
        cmd = envoy.run("pip install {}".format(str(requirement)))
        if cmd.status_code == 0:
            installed_packages = get_installed_pypackages()
            package = installed_packages[requirement.package]
            requirement.version = "=={}".format(package.version)
            if save:
                self.requirements["all"].add(requirement)
            if save_dev:
                self.requirements["dev"].add(requirement)
            if save or save_dev:
                self.requirements.save()
            return requirement
        else:
            fatal(cmd.std_err)
def AddResultsOptions(parser):
  group = optparse.OptionGroup(parser, 'Results options')
  group.add_option('--chartjson', action='store_true',
                   help='Output Chart JSON. Ignores --output-format.')
  group.add_option('--output-format', action='append', dest='output_formats',
                    choices=_OUTPUT_FORMAT_CHOICES, default=[],
                    help='Output format. Defaults to "%%default". '
                    'Can be %s.' % ', '.join(_OUTPUT_FORMAT_CHOICES))
  group.add_option('-o', '--output',
                    dest='output_file',
                    default=None,
                    help='Redirects output to a file. Defaults to stdout.')
  group.add_option('--output-dir', default=util.GetBaseDir(),
                    help='Where to save output data after the run.')
  group.add_option('--output-trace-tag',
                    default='',
                    help='Append a tag to the key of each result trace. Use '
                    'with html, buildbot, csv-pivot-table output formats.')
  group.add_option('--reset-results', action='store_true',
                    help='Delete all stored results.')
  group.add_option('--upload-results', action='store_true',
                    help='Upload the results to cloud storage.')
  group.add_option('--upload-bucket', default='internal',
                    choices=['public', 'partner', 'internal'],
                    help='Storage bucket to use for the uploaded results. '
                    'Defaults to internal. Supported values are: '
                    'public, partner, internal')
  group.add_option('--results-label',
                    default=None,
                    help='Optional label to use for the results of a run .')
  group.add_option('--suppress_gtest_report',
                   default=False,
                   help='Whether to suppress GTest progress report.')
  parser.add_option_group(group)