.collect(Collectors.groupingBy(Pair::getFirst, Collectors.mapping(Pair::getSecond, Collectors.toList())));
                    appendJson("search-field", searchFieldMap, buf).append(',');
                    final Map<String, List<String>> requestHeaderMap = entity.getRequestHeaderList().stream()

   * corresponding to each key appear in the same order as they are encountered.
   *
   * <p><b>{@code Stream} equivalent:</b> {@code stream.collect(Collectors.groupingBy(keyFunction))}
   * behaves similarly, but returns a mutable {@code Map<K, List<E>>} instead, and may not preserve
   * the order of entries.
   *
   * @param keyFunction the function used to produce the key for each value

- `IstioOperatorSpec`: The API directly defined in the
[IstioOperatorSpec proto](https://github.com/istio/api/blob/master/operator/v1alpha1/operator.proto),
including feature and component groupings, namespaces and enablement, and per-component K8s settings.
- Helm values.yaml API, implicitly defined through the various values.yaml files in the

	clusterCollector = newMinioClusterCollector(allMetricsGroups)
	bucketCollector = newMinioBucketCollector(bucketMetricsGroups)
}

// MetricNamespace is top level grouping of metrics to create the metric name.
type MetricNamespace string

// MetricSubsystem is the sub grouping for metrics within a namespace.
type MetricSubsystem string

const (
	bucketMetricNamespace    MetricNamespace = "minio_bucket"

Repetition  = "{" Expression "}" .
</pre>

<p>
Productions are expressions constructed from terms and the following
operators, in increasing precedence:
</p>
<pre class="grammar">
|   alternation
()  grouping
[]  option (0 or 1 times)
{}  repetition (0 to n times)
</pre>

<p>
Lower-case production names are used to identify lexical tokens.
Non-terminals are in CamelCase. Lexical tokens are enclosed in

Repetition  = "{" Expression "}" .
</pre>

<p>
Productions are expressions constructed from terms and the following
operators, in increasing precedence:
</p>
<pre class="grammar">
|   alternation
()  grouping
[]  option (0 or 1 times)
{}  repetition (0 to n times)
</pre>

<p>
Lowercase production names are used to identify lexical (terminal) tokens.
Non-terminals are in CamelCase. Lexical tokens are enclosed in

https://developer.mozilla.org/en-US/docs/Web/CSS/:focus-visible\n// and https://developer.paciellogroup.com/blog/2018/03/focus-visible-and-backwards-compatibility/\n[tabindex=\"-1\"]:focus:not(:focus-visible) {\n  outline: 0 !important;\n}\n\n\n// Content grouping\n//\n// 1. Add the correct box sizing in Firefox.\n// 2. Show the overflow in Edge and IE.\n\nhr {\n  box-sizing: content-box; // 1\n  height: 0; // 1\n  overflow: visible; // 2\n}\n\n\n//\n// Typography\n//\n\n// Remove top margins from headings\n//\n//...

https://developer.mozilla.org/en-US/docs/Web/CSS/:focus-visible\n// and https://developer.paciellogroup.com/blog/2018/03/focus-visible-and-backwards-compatibility/\n[tabindex=\"-1\"]:focus:not(:focus-visible) {\n  outline: 0 !important;\n}\n\n\n// Content grouping\n//\n// 1. Add the correct box sizing in Firefox.\n// 2. Show the overflow in Edge and IE.\n\nhr {\n  box-sizing: content-box; // 1\n  height: 0; // 1\n  overflow: visible; // 2\n}\n\n\n//\n// Typography\n//\n\n// Remove top margins from headings\n//\n//...