dap4/d4core/src/main/java/dap4/core/dmr/DapNode.java
public Map<String, DapAttribute> getAttributes()
    {
        if(attributes == null) attributes = new HashMap<String, DapAttribute>();
        return attributes;
    }
public Map<String, DapAttribute> getAttributes()
    {
        if(attributes == null) attributes = new HashMap<String, DapAttribute>();
        return attributes;
    }
attributes are not allowed on some node types