code: public static String getProperty(ArgumentUnit argumentUnit, String propertyName)
      {
          Properties properties = ArgumentUnitUtils.getProperties(argumentUnit);
          return (String) properties.get(propertyName);
      }
docs: Returns the property value
  
  @param argumentUnit argument component
  @param propertyName property name
  @return the value to which the specified key is mapped, or
  {@code null} if this map contains no mapping for the key