@Override
    public String getProperty(String name) {
        return System.getenv(TokenName.canonicalize(name));
    }
GuacamoleProperties implementation which reads all properties from
environment variables. The name of the environment variable corresponding to
any particular property is determined using
{@link TokenName#canonicalize(java.lang.String)}.
guacamole/src/main/java/org/apache/guacamole/SystemEnvironmentGuacamoleProperties.java