private void doRedBlackDelete()

in src/main/java/org/apache/commons/collections4/bidimap/TreeBidiMap.java [977:1033]
42 lines of code
13 McCabe index (conditional complexity)

    private void doRedBlackDelete(final Node<K, V> deletedNode) {
        for (final DataElement dataElement : DataElement.values()) {
            // if deleted node has both left and children, swap with
            // the next greater node
            if (deletedNode.getLeft(dataElement) != null && deletedNode.getRight(dataElement) != null) {
                swapPosition(nextGreater(deletedNode, dataElement), deletedNode, dataElement);
            }

            final Node<K, V> replacement = deletedNode.getLeft(dataElement) != null ?
                    deletedNode.getLeft(dataElement) : deletedNode.getRight(dataElement);

            if (replacement != null) {
                replacement.setParent(deletedNode.getParent(dataElement), dataElement);

                if (deletedNode.getParent(dataElement) == null) {
                    rootNode[dataElement.ordinal()] = replacement;
                } else if (deletedNode == deletedNode.getParent(dataElement).getLeft(dataElement)) {
                    deletedNode.getParent(dataElement).setLeft(replacement, dataElement);
                } else {
                    deletedNode.getParent(dataElement).setRight(replacement, dataElement);
                }

                deletedNode.setLeft(null, dataElement);
                deletedNode.setRight(null, dataElement);
                deletedNode.setParent(null, dataElement);

                if (isBlack(deletedNode, dataElement)) {
                    doRedBlackDeleteFixup(replacement, dataElement);
                }
            } else {

                // replacement is null
                if (deletedNode.getParent(dataElement) == null) {

                    // empty tree
                    rootNode[dataElement.ordinal()] = null;
                } else {

                    // deleted node had no children
                    if (isBlack(deletedNode, dataElement)) {
                        doRedBlackDeleteFixup(deletedNode, dataElement);
                    }

                    if (deletedNode.getParent(dataElement) != null) {
                        if (deletedNode == deletedNode.getParent(dataElement).getLeft(dataElement)) {
                            deletedNode.getParent(dataElement).setLeft(null, dataElement);
                        } else {
                            deletedNode.getParent(dataElement).setRight(null, dataElement);
                        }

                        deletedNode.setParent(null, dataElement);
                    }
                }
            }
        }
        shrink();
    }