pub fn with_env_key(env_key: &str) -> Option<Client> {
		match env::var_os(env_key) {
			Some(r) => Some(Client::new(r.into_string().unwrap())),
			None => None,
		}
	}
/// load api key from an environment variable
load api key from an environment variable
load api key from an environment variable
pub fn with_env_key(env_key: &str) -> Option<Client> {
		match env::var_os(env_key) {
			Some(r) => Some(Client::new(r.into_string().unwrap())),
			None => None,
		}
	}
pub fn with_env_key ( env_key : & str ) -> Option < Client > { match env :: var_os ( env_key ) { Some ( r ) => Some ( Client :: new ( r . into_string ( ) . unwrap ( ) ) ) , None => None , } }
load api key from an environment variable
load api key from an environment variable
env_key
&str