Go で YAML の動的キーを解析するにはどうすればよいですか?

<code class="go">package main

import (
    "fmt"

    "gopkg.in/yaml.v2"
)

type MajorVersion struct {
    Current                string   `yaml:"current"`
    MimeTypes              []string `yaml:"mime_types"`
    SkipVersionValidation  bool     `yaml:"skip-version-validation"`
    SkipMimeTypeValidation bool     `yaml:"skip-mime-type-validation"`
}

type Environment struct {
    SkipHeaderValidation bool
    Versions             map[string]MajorVersion
}

func (e *Environment) UnmarshalYAML(unmarshal func(interface{}) error) error {
    var params struct {
        SkipHeaderValidation bool `yaml:"skip-header-validation"`
    }
    if err := unmarshal(&amp;params); err != nil {
        return err
    }
    var versions map[string]MajorVersion
    if err := unmarshal(&amp;versions); err != nil {
        // Here we expect an error because a boolean cannot be converted to a MajorVersion
        if _, ok := err.(*yaml.TypeError); !ok {
            return err
        }
    }
    e.SkipHeaderValidation = params.SkipHeaderValidation
    e.Versions = versions
    return nil
}

func main() {
    var e map[string]Environment
    if err := yaml.Unmarshal([]byte(data), &amp;e); err != nil {
        fmt.Println(err.Error())
    }
    fmt.Printf("%#v\n", e)
}</code>