if (reference == null) {
      throw new NullPointerException();
    }
    return reference;
  }

  /**
   * Ensures that an object reference passed as a parameter to the calling method is not null.
   *
   * @param reference an object reference
   * @param errorMessage the exception message to use if the check fails; will be converted to a

  /*
   * We avoid using a method reference or lambda here for now:
   *
   * - method reference: Inside Google, CacheBuilder is used from the implementation of a custom
   *   ClassLoader that is sometimes used as a system classloader. That's a problem because
   *   method-reference linking tries to look up the system classloader, and it fails because there
   *   isn't one yet.
   *

      }
    }
  }

  /** A weakly referenced value that also has a reference to its containing entry. */
  interface WeakValueReference<K, V, E extends InternalEntry<K, V, E>> {
    /**
     * Returns the current value being referenced, or {@code null} if there is none (e.g. because

      }
    }
  }

  /** A weakly referenced value that also has a reference to its containing entry. */
  interface WeakValueReference<K, V, E extends InternalEntry<K, V, E>> {
    /**
     * Returns the current value being referenced, or {@code null} if there is none (e.g. because

  /*
   * We avoid using a method reference or lambda here for now:
   *
   * - method reference: Inside Google, CacheBuilder is used from the implementation of a custom
   *   ClassLoader that is sometimes used as a system classloader. That's a problem because
   *   method-reference linking tries to look up the system classloader, and it fails because there
   *   isn't one yet.
   *

Config(t){if("object"==typeof(t=super._getConfig(t)).reference&&!l(t.reference)&&"function"!=typeof t.reference.getBoundingClientRect)throw new TypeError(`${pt.toUpperCase()}: Option "reference" provided type "object" without a required "getBoundingClientRect" method.`);return t}_createPopper(){if(void 0===s)throw new TypeError("Bootstrap's dropdowns require Popper (https://popper.js.org)");let t=this._element;"parent"===this._config.reference?t=this._parent:l(this._config.reference)?t=c(this._c...

                // This means a module which is build has a dependency which has the same
                // groupId, artifactId, version and classifier coordinates. This is in consequence
                // a self reference or in other words a circular reference which can not being resolved.
                addViolation(
                        problems,
                        Severity.FATAL,
                        Version.V31,

     */
    protected String sanitizeDocumentContent(final String text) {
        if (StringUtil.isBlank(text)) {
            return text;
        }
        return text.replace("--- REFERENCE DOCUMENTS", "\\-\\-\\- REFERENCE DOCUMENTS")
                .replace("--- SEARCH RESULTS", "\\-\\-\\- SEARCH RESULTS")
                .replace("--- USER QUERY", "\\-\\-\\- USER QUERY")

//   example, one cannot use the output of "switch" node as input.
// - `inputs` and `outputs` cannot have reference types. Reference types are
//   not exposed through C API and are being replaced with Resources. We support
//   reference types inside function's body to support legacy code. Do not
//   use them in new code.
// - Every node in the function's body must have all of its inputs (including

   * accessed directly after this method returns. These conditions are ensured if the map is created
   * empty, passed directly to this method, and no reference to the map is retained, as illustrated
   * in the following code fragment:
   *
   * {@snippet :
   * Set<Object> identityHashSet = Sets.newSetFromMap(new IdentityHashMap<Object, Boolean>());
   * }
   *