Function env_reads 

pub fn env_reads() -> u64

getenv calls this module has made since the process started.

The counter behind the read-once law. Every path that reads the environment in this crate goes through [read_env], which bumps it; nothing else does. A caller — or a guard — can therefore prove that serving N objects cost zero environment reads, which is the only way to state the law as an assertion rather than as a comment.