code: public static String getEnvironmentString(String name, String defaultValue) {
          if (envVars == null) {
              throw new IllegalStateException("The environment vars must be provided before calling getEnvironmentString.");
          }
  
          return envVars.get(ENV_PREFIX + name) != null ? envVars.get(ENV_PREFIX + name) : defaultValue;
      }
docs: Retrieve string value for the environment variable name
  
  @param name The name of the variable without prefix
  @param defaultValue The default value if not found
  @return The value found, or the default if not found