code: private static boolean registerMissingProperty(String name) {
          final boolean previouslyReported = !PropertiesManager.missingProperties.add(name);
  
          if (!previouslyReported && log.isInfoEnabled()) {
              log.info("Property [" + name + "] was requested but not found.");
          }
          return previouslyReported;
      }
docs: Registers that a given property was sought but not found. Currently adds the property to the
  set of missing properties and logs if this is the first time the property has been requested.
  
  @param name - the name of the missing property
  @return true if the property was previously registered, false otherwise