code: ConstructorParamExpressionBuilder param() {
      return new ConstructorParamExpressionBuilder(
          new ExpressionHandler<ConstructorCallBuilder>() {
            public ConstructorCallBuilder handleExpression(Expression e) {
              return new ConstructorCallBuilder(
                  factory,
                  expressionHandler,
                  parameters.append(e));
            }
      });
    }
docs: pass a parameter to the constructor
  @return the expressionbuilder to build the parameter value