Function init 

pub fn init()

Initialize a global tracing logger.

• The logger will print enabled tracing events and spans to stderr.
• You can change the log level or module filtering with an appropriate RUST_LOG env var set. Read more about the syntax here: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html

Panics if a logger is already initialized. This will fail if used in tests, since multiple test threads will compete to set the global logger.