code: public static String tryGetGlobalProperty(String key, String defaultValue) {
          try {
              String value = System.getenv(formatEnvironmentVariable(key));
              if (value == null) {
                  value = tryGetProperty(key, defaultValue);
              }
              return value;
          } catch (SecurityException e) {
              logger.error("Could not get value of global property {} due to SecurityManager. Using default value.", key, e);
              return defaultValue;
          }
      }
docs: Get a global string property. This method will first try to get the value from an
  environment variable and if that does not exist it will look up a system property.
  @param key Name of the variable
  @param defaultValue Returned if neither env var nor system property are defined
  @return String the value of the Environment or System Property if defined, the given
  default value otherwise