* regression</a> of {@code y} as a function of {@code x}. The count must be greater than one, and
   * either the {@code x} or {@code y} data must have a non-zero population variance (i.e. {@code
   * xStats().populationVariance() > 0.0 || yStats().populationVariance() > 0.0}). The result is
   * guaranteed to be horizontal if there is variance in the {@code x} data but not the {@code y}

	var langs []Language
	if err := DB.Find(&langs, "code = ?", lang.Code).Error; err != nil {
		t.Errorf("no error should happen when find languages with code, but got %v", err)
	} else if len(langs) != 1 {
		t.Errorf("should only find only 1 languages, but got %+v", langs)
	}

	lang3 := Language{Code: "upsert", Name: "Upsert"}
	if err := DB.Clauses(clause.OnConflict{
		Columns:   []clause.Column{{Name: "code"}},

    /**
     * Traverses this node and potentially its children using the specified visitor.
     *
     * @param visitor the visitor to call back, must not be {@code null}
     * @return {@code true} to visit siblings nodes of this node as well, {@code false} to skip siblings
     */
    boolean accept(@Nonnull NodeVisitor visitor);

    /**
     * Returns a new tree starting at this node, filtering the children.

	Shared     = flag.Bool("shared", false, "generate code that can be linked into a shared library")
	Dynlink    = flag.Bool("dynlink", false, "support references to Go symbols defined in other shared libraries")
	Linkshared = flag.Bool("linkshared", false, "generate code that will be linked against Go shared libraries")
	AllErrors  = flag.Bool("e", false, "no limit on number of errors reported")

 *
 * <p>Additional escapers implementations are found in the applicable packages: {@link
 * com.google.common.html.HtmlEscapers} in {@code com.google.common.html}, {@link
 * com.google.common.xml.XmlEscapers} in {@code com.google.common.xml}, and {@link
 * com.google.common.net.UrlEscapers} in {@code com.google.common.net}.
 *
 * <p>This package is a part of the open-source <a href="https://github.com/google/guava">Guava</a>
 * library.
 */

 * code changes, you can use <a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/guava/latest/com.github.benmanes.caffeine.guava/com/github/benmanes/caffeine/guava/CaffeinatedGuava.html">its
 * {@code CaffeinatedGuava} adapter class</a>, which lets you build a Guava {@code Cache} or a Guava
 * {@code LoadingCache} backed by a Guava {@code CacheLoader}.
 *
 * <p>Caffeine's API for asynchronous operations uses {@code CompletableFuture}: <a

 *
 * This works because those types each implement {@code PredecessorsFunction}. It will also work
 * with any other implementation of this interface.
 *
 * <p>If you have your own graph implementation based around a custom node type {@code MyNode},
 * which has a method {@code getParents()} that retrieves its predecessors in a graph:
 *
 * <pre>{@code
 * someGraphAlgorithm(startNode, MyNode::getParents);
 * }</pre>
 *

    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}!
   */
  @CanIgnoreReturnValue
  private Node<K, V> addNode(
      @ParametricNullness K key,

@J2ktIncompatible
@ElementTypesAreNonnullByDefault
public final class Enums {

  private Enums() {}

  /**
   * Returns the {@link Field} in which {@code enumValue} is defined. For example, to get the {@code
   * Description} annotation on the {@code GOLF} constant of enum {@code Sport}, use {@code
   * Enums.getField(Sport.GOLF).getAnnotation(Description.class)}.
   *
   * @since 12.0
   */
  @GwtIncompatible // reflection

   *         <li>{@code adjacentNodes(node)}: Stable order
   *         <li>{@code predecessors(node)}: Connecting edge insertion order
   *         <li>{@code successors(node)}: Connecting edge insertion order
   *         <li>{@code incidentEdges(node)}: Stable order
   *         <li>{@code inEdges(node)}: Edge insertion order
   *         <li>{@code outEdges(node)}: Edge insertion order
   *         <li>{@code adjacentEdges(edge)}: Stable order