Method is_dev

rust/src/lib.rs:789–791

(&self, browser_version: &str)

    }

    fn is_dev(&self, browser_version: &str) -> bool {
        browser_version.eq_ignore_ascii_case(DEV)
    }

    fn is_browser_version_nightly(&self) -> bool {
        self.is_nightly(self.get_browser_version())