code: def is_downloadable(self):
          
          is_plugin_avaiable = False
          if self.is_dnf:
              is_plugin_avaiable = self.is_package_installed(
                                   'dnf-plugins-core')
          else:
              """ yum environment.
              Make sure
              # yum -y --downloadonly --downloaddir=. install package_name
              is only available for root user.
  
              yumdownloader in yum-utils is available for normal user.
              https://access.redhat.com/solutions/10154
              """
              is_plugin_avaiable = self.is_package_installed(
                                   'yum-utils')
          return is_plugin_avaiable
docs: Return if rpm is downloadable by the package command.
  
          Check if dnf or yum plugin package exists.