code: public String getProperty(final String key) {
          if (hasProperty(key)) {
              return properties.getProperty(key);
          } else {
              throw new PropertyLookupException("property not found: " + key);
          }
      }
docs: Get the property per specified key
  
  @param key name of the property
  @return Value of the property
  @throws PropertyLookupException thrown if lookup fails for specified key