question: public void registerWildcard ( Symbol holder , JCWildcard wildcard ) { if ( wildcard . getBound ( ) == null ) { return ; } List < JCWildcard > l = wildcards . get ( holder ) ; if ( l == null ) { l = new ArrayList < > ( ) ; wildcards . put ( holder , l ) ; } l . add ( wildcard ) ; wildcardNames . put ( wildcard , "__T" + l . size ( ) ) ; }
target:  Registers a wilcard for a given container (type parameterized element).