code: def install_gem(gem):
      
      with settings(hide('warnings', 'running', 'stdout', 'stderr'),
                    warn_only=False, capture=True):
          # convert 0 into True, any errors will always raise an exception
          return not bool(
              run("gem install %s --no-rdoc --no-ri" % gem).return_code)
docs: install a particular gem