使用gocheck测试go（golang）代码，套件功能如何工作？

I was trying to use gocheck to test my go code. I was guiding myself with the following example (similar to the one provided by their website):

package hello_test

import (
    "testing"

    gocheck "gopkg.in/check.v1"
)

// Hook up gocheck into the "go test" runner.
func Test(t *testing.T) {
    gocheck.TestingT(t)
}

type MySuite struct{} //<==== Does the struct have to be named that way, what if we have multiple of these and register them, is it a problem?

var _ = gocheck.Suite(&MySuite{}) // <==== What does this line do?

func (s *MySuite) TestHelloWorld(c *gocheck.C) {
    c.Assert(42, gocheck.Equals, "42")
    c.Check(42, gocheck.Equals, 42)
}

However, there are some lines I am not sure I understand even after reading the documentation. Why is the line type MySuite struct{} needed and even more of an interesting line, why is var _ = gocheck.Suite(&MySuite{}) needed? The first one, its easy to infer that one probably has to declare that struct first and create functions that will run the tests if implemented with the signature as shown. However, the second line beats me. I have literally no idea why its needed. The documentation says:

Suite registers the given value as a test suite to be run. Any methods starting with the Test prefix in the given value will be considered as a test method.

However, I am not sure about a lot of things. For instance, is there a problem if I run this function with multiple MySuite structs in the same file? Is there anything special about the type MySuite struct? Could the gocheck testing suite work even with some different struct being registered? Basically, how many times can we register a struct in one file and will it still work?

The gocheck.Suite function has the side effect of registering the given suite value with the gocheck package. Internally, it just adds the the suite to a slice of registered test suites. You could get the same effect with:

func init() {
    gocheck.Suite(&MySuite{})
}

Either form should work, so it is just a matter of style.

The tests in the registered test suites are run when you call gocheck.TestingT. You do this in your test called Test, which will be picked up by Go's testing framework. This is how gocheck tests are integrated into the testing framework. Note that you only need a single invocation of TestingT to run all test suites: not one for each test suite.