code: public String getProperty(String name, String defaultValue) {
          String value = getProperty(name);
          return value != null ? value : defaultValue;
      }
docs: Get value of given property, returning given default value if the
  property has not been set.
  
  @param name
  name of the property to get
  @param defaultValue
  default value to return if propery is not set
  @return the value of the named property, or the default value if the
  property has not been set