Unable to set FriendlyName for custom attribute

Trying to implement custom attribute manager. Just as described at https://docs.jboss.org/author/display/PLINK/User-defined+SAML+Assertion+Attributes

So a class that implements SAML2AttributeManager is written, it's FQN is passed to AttributeManager attribute of PicketLinkIDP element at picketlink.xml. It works as intended except that custom attribute in SAML response document has two attributes - Name and FriendlyName - with same values.

attr.setFriendlyName("myFriendlyNameValue"); added to the custom attribute manager does nothing - Name and FriendlyName have same values of Name.