code: public Property get(String key) {
          for (Property property : properties) {
              if (property.getKey().equals(key)) {
                  return property;
              }
          }
          return null;
      }
docs: Gets property for a given property key
  @param key the key whose associated property to be returned
  @return the property to which the specified key is mapped, or null if this property with given key not found