Context variables are variables that can have different values depending on their context. They are similar to Thread-Local Storage in which each execution thread may have a different value for a variable. However, with context variables, there may be several contexts in one execution thread. The main use case for context variables is keeping track of variables in concurrent asynchronous tasks. -- https://realpython.com/python37-new-features/#context-variables
"""Example copied verbatim from Real Python."""
import contextvars
name = contextvars.ContextVar("name")
contexts = list()