'Upgrade the plugin.
Args:
remote (string): Remote reference to upgrade to. The
``:latest`` tag is optional and is the default if omitted.
Default: this plugin\'s name.
Returns:
A generator streaming the decoded API logs'

def upgrade(self, remote=None):

    if self.enabled:
        raise errors.DockerError('Plugin    must    be    disabled    before    upgrading.')
    if (remote is None):
        remote = self.name
    privileges = self.client.api.plugin_privileges(remote)
    for d in self.client.api.upgrade_plugin(self.name, remote, privileges):
        (yield d)
    self._reload()
