Redirecting stdout into an `IOBuffer`

julia_redirect_stdout_to_IOBuffer.jl

"""
    redirect_stdout(f::Function, stream::IOBuffer)

```julia
julia> buf = IOBuffer();
julia> redirect_stdout(buf) do
           print("Hello, World!")
       end
julia> String(take!(buf))
"Hello, World!"
```
"""
function Base.redirect_stdout(f::Function, stream::IOBuffer)
    backup = stdout
    rd, wr = redirect_stdout()
    try
        f()
    finally
        redirect_stdout(backup)
        close(wr)
        write(stream, read(rd))
        close(rd)
    end
end