@Override
    public String toString() {
        StringBuilder sb = new StringBuilder();
        sb.append(name).append(": ").append(type);
        if (builtIn != null) {
            sb.append("; builtIn(").append(builtIn).append(")");
        }
        if (required) {
            sb.append("; required");
        }
        getDeprecated().ifPresent(dep -> sb.append("; ").append(deprecated).append("!"));
        return sb.toString();
    }
Gets the parameter's default value.

@return returns the optional default value.
smithy-rules-engine/src/main/java/software/amazon/smithy/rulesengine/language/syntax/parameters/Parameter.java