@Override
    public void addFirst(E e) {
      assertTrue(Thread.holdsLock(mutex));
      delegate.addFirst(e);
    }

    @Override
    public void addLast(E e) {
      assertTrue(Thread.holdsLock(mutex));
      delegate.addLast(e);
    }

    @Override
    public boolean offerFirst(E e) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.offerFirst(e);
    }

func (limit Limit) Build(builder Builder) {
	if limit.Limit != nil && *limit.Limit >= 0 {
		builder.WriteString("LIMIT ")
		builder.AddVar(builder, *limit.Limit)
	}
	if limit.Offset > 0 {
		if limit.Limit != nil && *limit.Limit >= 0 {
			builder.WriteByte(' ')
		}
		builder.WriteString("OFFSET ")
		builder.AddVar(builder, limit.Offset)
	}
}

// MergeClause merge order by clauses
func (limit Limit) MergeClause(clause *Clause) {

  @Override
  protected abstract Deque<E> delegate();

  @Override
  public void addFirst(@ParametricNullness E e) {
    delegate().addFirst(e);
  }

  @Override
  public void addLast(@ParametricNullness E e) {
    delegate().addLast(e);
  }

  @Override
  public Iterator<E> descendingIterator() {
    return delegate().descendingIterator();
  }

  @Override
  @ParametricNullness
  public E getFirst() {

}

// Quote returns quoted value
func (stmt *Statement) Quote(field interface{}) string {
	var builder strings.Builder
	stmt.QuoteTo(&builder, field)
	return builder.String()
}

// AddVar add var
func (stmt *Statement) AddVar(writer clause.Writer, vars ...interface{}) {
	for idx, v := range vars {
		if idx > 0 {
			writer.WriteByte(',')
		}

		switch v := v.(type) {
		case sql.NamedArg:

type Writer interface {
	WriteByte(byte) error
	WriteString(string) (int, error)
}

// Builder builder interface
type Builder interface {
	Writer
	WriteQuoted(field interface{})
	AddVar(Writer, ...interface{})
	AddError(error) error
}

// Clause
type Clause struct {
	Name                string // WHERE
	BeforeExpression    Expression
	AfterNameExpression Expression

        if (children != null) {
            for (String v : children) {
                DfsState state = stateMap.putIfAbsent(v, DfsState.VISITING);
                if (state == null) {
                    cycle.addLast(v);
                    List<String> ret = visitCycle(graph, graph.get(v), stateMap, cycle);
                    if (ret != null) {
                        return ret;
                    }

		}
		builder.WriteByte(')')

		builder.WriteString(" VALUES ")

		for idx, value := range values.Values {
			if idx > 0 {
				builder.WriteByte(',')
			}

			builder.WriteByte('(')
			builder.AddVar(builder, value...)
			builder.WriteByte(')')
		}
	} else {
		builder.WriteString("DEFAULT VALUES")
	}
}

// MergeClause merge values clauses
func (values Values) MergeClause(clause *Clause) {

	if len(set) > 0 {
		for idx, assignment := range set {
			if idx > 0 {
				builder.WriteByte(',')
			}
			builder.WriteQuoted(assignment.Column)
			builder.WriteByte('=')
			builder.AddVar(builder, assignment.Value)
		}
	} else {
		builder.WriteQuoted(Column{Name: PrimaryKey})
		builder.WriteByte('=')
		builder.WriteQuoted(Column{Name: PrimaryKey})
	}
}

// MergeClause merge assignments clauses

        for (Vertex v : children) {
            DfsState state = stateMap.putIfAbsent(v, DfsState.VISITING);
            if (state == null) {
                cycle.addLast(v.label);
                List<String> ret = visitCycle(v.children, stateMap, cycle);
                if (ret != null) {
                    return ret;
                }
                cycle.removeLast();

        if (currentlyBuilding.contains(className)) {
            throw new RuntimeException("Cycle building $className. Currently building $currentlyBuilding")
        }
        currentlyBuilding.addLast(className)
        try {
            ClassMetaData classMetaData = classMetaData.find(className)
            if (!classMetaData) {
                if (!className.contains('.internal.')) {