安装ChAMP包时提示报错：there is no package called 'GO.db'
这个报错看起来问题不大，缺啥补啥。那就安装GO.db包。
于是我麻溜的写下安装命令行BiocManager::install("GO.db")
此时又报错了:

Error in download.file(url, destfile, method, mode = "wb", ...) :
download from 'https://bioconductor.org/packages/3.11/data/annotation/src/contrib/GO.db_3.11.1.tar.gz' failed

最后还是谷歌搞定的，解决方案在这里：https://stackoverflow.com/questions/55298366/cannot-install-go-db-in-biocmanager
分三步走：

1. BiocManager::install("Biobase")

2. BiocManager::install("GO.db")

Respond "y" when it asks if you want to update all packages.

3. BiocManager::valid("GO.db")

搞定！