How command pool works? and How can we redirect to payment gateway? Magento 2

curl redirect magento2 payment-gateway payment

We should perform CURL action in ClientMock - placeRequest().The flow of the payment gateway command pool is:

Request Builder (handle order information), implement Magento\Payment\Gateway\Request\BuilderInterface;
ClientMock process payment action
ResponseValidator (extends AbstractValidator), decides if payment is successful or not
Response Handler (implements HandlerInterface), perform the final action, you may set additional information for the payment here.

CodeHunter