public PsiSubstitutor createSubstitutor(boolean preferSubst) {
      PsiSubstitutor theSubst = mySubst;
      if (preferSubst) {
        myMapping.keySet().removeAll(mySubst.getSubstitutionMap().keySet());
      }
      for (final PsiTypeParameter parm : myMapping.keySet()) {
        theSubst = theSubst.put(parm, myMapping.get(parm));
      }
      return theSubst;
    }
public PsiSubstitutor createSubstitutor(boolean preferSubst)