“ _ Render”是什么意思? [重复]

Code in there

我的问题是:

  1. “ _ Render”之类的变量是什么意思?
  2. 如何在我的程序中使用它?
package render

// Render interface is to be implemented by JSON, XML, HTML, YAML and so on.
type Render interface {} //omitted

var (
    _ Render     = JSON{}
    _ Render     = IndentedJSON{}
    // someone like this... ommitted
)
...