DownloadToStream() function's description, please?

[IlyaRabyy]

Colleagues,

Going through the other developers' codes in C#, came across the function in subject.
Have never seen this DownloadToStream() function before, tried to find its description on MSDN - bubkis!
The only thing the search gave me was an example in F# and relevant to Azire blob handling:

https://docs.microsoft.com/en-us/dotnet/fsharp/using-fsharp-on-azure/blob-storage

Remind you: I found this function in the C# code, not F#! And besides, this program has nothing to do with Azure.
Broaden the search to the entire

http://WWW -

got no meaningful results but/and again: all about Azure/Blob handling. But those guys used it in the C# .NET code!

Could anyone help me to find regular, comprehensive Help-like description of this function relevant to C#? Or at least description relevant to .NET realm?

TIA!

Regards,

Ilya

P.S. Found it: it's those guys "very own" custom function in a custom class in a custom library.
My apologies for wasting your time!