@Override
    public Void visit(ParamExpression<?> param, Void context) {
        String paramLabel;
        if (param.isAnon()) {
            paramLabel = anonParamPrefix + param.getName();
        } else {
            paramLabel = paramPrefix + param.getName();
        }
        getConstantToLabel().put(param, paramLabel);
        constants.add(param);
        serializeConstant(constants.size(), paramLabel);
        return null;
    }
Generate a constant value under which to register a new constant in {@link #getConstantToLabel()}.

@param value the constant value or parameter to create a constant for
@return the generated label
querydsl-core/src/main/java/com/querydsl/core/support/SerializerBase.java