Secure networking classes with an optional
use the defaultContext object if the parameter is omitted.
This object can also be accessed, and modified, directly.
Each isolate has a different defaultContext object.
The defaultContext object uses a list of well-known trusted
certificate authorities as its trusted roots. On Linux and Windows, this
list is taken from Mozilla, who maintains it as part of Firefox. On,
MacOS, iOS, and Android, this list comes from the trusted certificates
stores built in to the platforms.
external static SecurityContext get defaultContext;