@Override
    protected boolean doSetValue(String value) {
        if (! value.equalsIgnoreCase("false") && ! value.equalsIgnoreCase("true")) {
            return false;
        }
        this.value = Boolean.valueOf(value);
        return true;
    }
The BooleanNode class represents a boolean in a configuration tree.
config-lib/src/main/java/com/yahoo/config/BooleanNode.java