public static ASTASMethod newInterfaceMethod(String name, Visibility visibility, String returnType) {
		LinkedListTree def = ASTUtils.newImaginaryAST(AS3Parser.METHOD_DEF);
		LinkedListTree annos = ASTUtils.newPlaceholderAST(AS3Parser.ANNOTATIONS);
		def.addChildWithTokens(annos);
		def.addChildWithTokens(ModifierUtils.toModifiers(visibility));
		def.appendToken(TokenBuilder.newFunction());
		def.appendToken(TokenBuilder.newSpace());
		LinkedListTree acc = ASTUtils.newPlaceholderAST(AS3Parser.ACCESSOR_ROLE);
		def.addChildWithTokens(acc);
		LinkedListTree methName = ASTUtils.newAST(AS3Parser.IDENT, name);
		def.addChildWithTokens(methName);
		def.addChildWithTokens(ASTUtils.newParentheticAST(AS3Parser.PARAMS, AS3Parser.LPAREN, "(", AS3Parser.RPAREN, ")"));
		if (returnType != null) {
			def.addChildWithTokens(AS3FragmentParser.parseTypeSpec(returnType));
		}
		def.appendToken(TokenBuilder.newSemi());

	public static ASAssignmentExpression newAssignExpression(LinkedListToken op, Expression left, Expression right) {
		LinkedListTree ast = ASTUtils.newAST(op);
		LinkedListTree leftExpr = ((ASTExpression)left).getAST();
		assertNoParent("left-hand expression", leftExpr);
		LinkedListTree rightExpr = ((ASTExpression)right).getAST();
		if (precidence(ast) < precidence(leftExpr)) {
			leftExpr = parenthise(leftExpr);
		}
		if (precidence(ast) < precidence(rightExpr)) {
			rightExpr = parenthise(rightExpr);
		}
		// don't use addChildWithTokens(); special handling below,
		ast.addChild(leftExpr);
		ast.addChild(rightExpr);
		leftExpr.getStopToken().setNext(op);
		rightExpr.getStartToken().setPrev(op);
		ast.setStartToken(leftExpr.getStartToken());
		ast.setStopToken(rightExpr.getStopToken());
		spaceEitherSide(op);
		return new ASTASAssignmentExpression(ast);

		LinkedListTree impls = ASTUtils.findChildByType(ast, AS3Parser.EXTENDS);
		int count = 0;
		for (ASTIterator i=new ASTIterator(impls); i.hasNext(); ) {
			LinkedListTree iface = i.next();
			String name = ASTUtils.identText(iface);
			if (name.equals(interfaceName)) {
				if (i.hasNext()) {
					ASTUtils.removeTrailingWhitespaceAndComma(iface.getStopToken());
				} else if (count == 0) {
					// no interfaces left, so remove the
					// 'implements' clause completely,
					ast.deleteChild(ast.getIndexOfChild(impls));
					break;
				}
				i.remove();
				if (i.hasNext()) {
					count++;
				}
				break;
			}
			count++;
		}
	}

	public ASMethod newMethod(String name, Visibility visibility, String returnType) {