code: @VisibleForTesting
      Map<String, String> loadBaseProperties() throws IOException {
          final Properties props = new Properties();
          for (final String property: StringUtils.split(configuration.getProperty(GeneralOption.SONAR_PROPERTIES), ',')){
              final File propertyFile = new File(StringUtils.strip(property));
              log.info("Loading {}", propertyFile.getAbsolutePath());
              props.load(new FileInputStream(propertyFile));
          }
          return (Map)props;
      }
docs: Load base sonar configuration files specified by GeneralOption.SONAR_PROPERTIES
  configuration key
  @return a Properties instance
  @throws IOException