code: public PropertiesLoaderBuilder addProperty(String name, String value) {
          props.put(name, value);
          return this;
      }
docs: Adds a new property. Giving both name and value.
  This methods does not lookup in the Spring Context, it only adds property and value as given.
  
  @param name to be added in the properties
  @param value to be added in the properties
  @return PropertyLoaderBuilder to continue the builder chain