// ----------------------------------------------------------------------
        // Requirements
        // ----------------------------------------------------------------------

        PlexusConfiguration[] requirements = c.getChild("requirements").getChildren("requirement");

        for (PlexusConfiguration requirement : requirements) {
            ComponentRequirement cr = new ComponentRequirement();

    /**
     * Let the toolchain decide if it matches requirements defined
     * in the toolchain plugin configuration.
     *
     * @param requirements key value pair, may not be {@code null}
     * @return {@code true} if the requirements match, otherwise {@code false}
     */
    boolean matchesRequirements(Map<String, String> requirements);

    public List<Toolchain> getToolchains(Session session, String type, Map<String, String> requirements)
            throws ToolchainManagerException {
        MavenSession s = InternalMavenSession.from(session).getMavenSession();
        List<org.apache.maven.toolchain.Toolchain> toolchains =
                toolchainManagerPrivate.getToolchains(s, type, requirements);
        return new MappedList<>(toolchains, this::toToolchain);
    }

            options.addStringOption("source", "8");
            options.tags("apiNote:a:API Note:", "implSpec:a:Implementation Requirements:", "implNote:a:Implementation Note:");
            // TODO: This breaks the provider
            options.links(javadocs.getJavaApi().get().toString(), javadocs.getGroovyApi().get().toString());

    return equivalent(t, u);
  }

  /**
   * Implemented by the user to determine whether {@code a} and {@code b} are considered equivalent,
   * subject to the requirements specified in {@link #equivalent}.
   *
   * <p>This method should not be called except by {@link #equivalent}. When {@link #equivalent}

     * <p>
     * Types of the Java SE API, types of the Kotlin stdlib, and Groovy's
     * GString type are not supported because they meet neither of those
     * requirements.
     *
     * @param validationContext the validation context
     * @param propertyName the name of the property
     * @param beanType the type of the bean
     */
    public static void validateBeanType(

  // have two requirements that significantly complicate their design.
  // 1. Cancellation should propagate from the returned future to the input future(s).
  // 2. The returned futures shouldn't unnecessarily 'pin' their inputs after completion.
  //
  // A consequence of these requirements is that the delegate futures cannot be stored in
  // final fields.
  //

  public final int hash(@CheckForNull T t) {
    if (t == null) {
      return 0;
    }
    return doHash(t);
  }

  /**
   * Implemented by the user to return a hash code for {@code t}, subject to the requirements
   * specified in {@link #hash}.
   *
   * <p>This method should not be called except by {@link #hash}. When {@link #hash} calls this
   * method, {@code t} is guaranteed to be non-null.
   *

  // have two requirements that significantly complicate their design.
  // 1. Cancellation should propagate from the returned future to the input future(s).
  // 2. The returned futures shouldn't unnecessarily 'pin' their inputs after completion.
  //
  // A consequence of these requirements is that the delegate futures cannot be stored in
  // final fields.
  //

     * nature of the read operations in Map. For example, no operation can reveal that the table
     * has grown but the threshold has not yet been updated, so there are no atomicity requirements
     * for this with respect to reads.
     *
     * As a guide, all critical volatile reads and writes to the count field are marked in code
     * comments.
     */