Function format 

pub fn format() -> Format

Available on crate features fmt and std and tracing only.

Returns the default configuration for an event formatter.

Methods on the returned event formatter can be used for further configuration. For example:

let format = tracing_subscriber::fmt::format()
    .without_time()         // Don't include timestamps
    .with_target(false)     // Don't include event targets.
    .with_level(false)      // Don't include event levels.
    .compact();             // Use a more compact, abbreviated format.

// Use the configured formatter when building a new subscriber.
tracing_subscriber::fmt()
    .event_format(format)
    .init();