ghttp: Can support setting default values ​​for header?

[nilsir]

Is your feature request related to a problem?

Option Yes

Describe the solution you'd like

I want to set a default value when the header information is empty

Describe alternatives you've considered

# now is 
language := r.GetHeader("lang")
if language == "" {
    language = "zh-CN"
}

# replace is
r.GetHeader("lang", "zh-CN") 

Additional

No response

[gqcn]

Good proposal!

[github-actions]

Hello @nilsir. We like your proposal/feedback and would appreciate a contribution via a Pull Request by you or another community member. We thank you in advance for your contribution and are looking forward to reviewing it!
你好 @nilsir。我们喜欢您的提案/反馈，并希望您或其他社区成员通过拉取请求做出贡献。我们提前感谢您的贡献，并期待对其进行审查。