presto-main/src/main/java/io/prestosql/server/PluginManagerConfig.java/PluginManagerConfig/setPlugins
class PluginManagerConfig:    @Config("plugin.bundles")
    public PluginManagerConfig setPlugins(String plugins)
    {
        if (plugins == null) {
            this.plugins = null;
        }
        else {
            this.plugins = ImmutableList.copyOf(Splitter.on(',').omitEmptyStrings().trimResults().split(plugins));
        }
        return this;
    }