You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: lib.rs
    path of file: ./repos/linkerd2-proxy/linkerd/tracing/src
    
    the code of the file until where you have to start completion: #![deny(rust_2018_idioms, clippy::disallowed_methods, clippy::disallowed_types)]
#![forbid(unsafe_code)]

pub mod access_log;
pub mod level;
#[cfg(feature = "stream")]
pub mod stream;
pub mod test;
mod uptime;

use self::uptime::Uptime;
use linkerd_error::Error;
use std::str;
use tokio::time;
use
    
    pub fn from_env() -> Self {
        let now = time::Instant::now();
        Self {
            filter: std::env::var(ENV_LOG_LEVEL)
                .ok()
                .unwrap_or_else(|| DEFAULT_LOG_LEVEL.to_string()),
            format: std::env::var(ENV_LOG_FORMAT)
                .ok()
                .unwrap_or_else(|| DEFAULT_LOG_FORMAT.to_string()),
            access_log: Self::access_log_format(),
            start_time: Some(now),
            is_test: false,
        }
    }