}
	if w.Endpoint.IsEmpty() {
		return errors.New("endpoint empty")
	}
	if w.ClientCert != "" && w.ClientKey == "" || w.ClientCert == "" && w.ClientKey != "" {
		return errors.New("cert and key must be specified as a pair")
	}
	return nil
}

// WebhookTarget - Webhook target.
type WebhookTarget struct {
	activeRequests int64
	totalRequests  int64
	failedRequests int64

	lazyInit lazyInit

 *
 * All start/connect/acquire events will eventually receive a matching end/release event, either
 * successful (non-null parameters), or failed (non-null throwable). The first common parameters of
 * each event pair are used to link the event in case of concurrent or repeated events e.g.
 * `dnsStart(call, domainName)` → `dnsEnd(call, domainName, inetAddressList)`.
 *
 * Events are typically nested with this structure:
 *

        final List<Pair<FormScheme, Credentials>> formSchemeList = new ArrayList<>();
        for (final Authentication authentication : siteCredentialList) {
            final AuthScheme authScheme = authentication.getAuthScheme();
            if (authScheme instanceof FormScheme) {
                formSchemeList.add(new Pair<>((FormScheme) authScheme, authentication.getCredentials()));

)

// qProp contains analysis info about an SQL term.
type qProp struct {
	isAggregation, isRowFunc bool

	err error
}

// `combine` combines a pair of `qProp`s, so that errors are
// propagated correctly, and checks that an aggregation is not being
// combined with a row-function term.
func (p *qProp) combine(q qProp) {
	switch {
	case p.err != nil:
		// Do nothing

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A collection that associates an ordered pair of keys, called a row key and a column key, with a
 * single value. A table may be sparse, with only a small fraction of row key / column key pairs
 * possessing a corresponding value.
 *
 * <p>The mappings corresponding to a given row key may be viewed as a {@link Map} whose keys are

      } else {
        utf8Length += 2;
        // We can't use Character.isSurrogate(c) here and below because of GWT.
        if (MIN_SURROGATE <= c && c <= MAX_SURROGATE) {
          // Check that we have a well-formed surrogate pair.
          if (Character.codePointAt(sequence, i) == c) {
            throw new IllegalArgumentException(unpairedSurrogateMsg(i));
          }
          i++;
        }
      }
    }
    return utf8Length;
  }

  }

  private LinkedListMultimap(Multimap<? extends K, ? extends V> multimap) {
    this(multimap.keySet().size());
    putAll(multimap);
  }

  /**
   * Adds a new node for the specified key-value pair before the specified {@code nextSibling}
   * element, or at the end of the list if {@code nextSibling} is null. Note: if {@code nextSibling}
   * is specified, it MUST be for a node for the same {@code key}!
   */

 * **Exchange** carries a single HTTP request/response pair.

 * **ExchangeFinder** chooses which connection carries each exchange. Where possible it will use the same connection for all exchanges in a single call. It prefers reusing pooled connections over establishing new connections.      

   * The caller is responsible for <a
   * href="https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#multipart-form-data">replacing
   * any unpaired carriage return or line feed characters with a CR+LF pair</a> on any non-file
   * inputs before escaping them with this escaper.
   *
   * <p>When escaping a String, the following rules apply:
   *
   * <ul>

  private static <N, V> GraphConnections<N, V> connectionsOf(ValueGraph<N, V> graph, N node) {
    Function<N, V> successorNodeToValueFn =
        (N successorNode) ->
            // requireNonNull is safe because the endpoint pair comes from the graph.
            requireNonNull(graph.edgeValueOrDefault(node, successorNode, null));
    return graph.isDirected()
        ? DirectedGraphConnections.ofImmutable(