code: public static Integer getIntegerProperty(Configuration config, String key) throws DeployerConfigurationException {
          return getIntegerProperty(config, key, null);
      }
docs: Returns the specified Integer property from the configuration
  
  @param config the configuration
  @param key    the key of the property
  @return the Integer value of the property, or null if not found
  @throws DeployerConfigurationException if an error occurred