adding mapping without using the attribute. This is util when trying to map two object that weren't coded by user, when mapping two objects located on 3-party libraries
Merge commit '00f70f14e6192aa5e9f940a2093cb196a72ee57d'

# By NIcolas A Perez
# Via NIcolas A Perez
* commit '00f70f14e6192aa5e9f940a2093cb196a72ee57d':
  Update README.md