code: public boolean hasUserGrant(Grant grant,BaasUser user){
          if (user==null) throw new IllegalArgumentException("username cannot be null");
          return hasUserGrant(grant, user.getName());
      }
docs: Checks if the {@code user} has the specified {@code grant}
  @param grant a {@link com.baasbox.android.Grant}
  @param user a {@link com.baasbox.android.BaasUser}
  @return