v = ((RubyHash)opt).op_aref(context, runtime.newSymbol("undef"));
if (v.isNil()) {
} else if (v.toString().equals("replace")) {
ecflags |= EConvFlags.UNDEF_REPLACE;
} else {
throw runtime.newArgumentError("unknown value for undefined character option");
}
v = ((RubyHash)opt).op_aref(context, runtime.newSymbol("replace"));
if (!v.isNil() && (ecflags & EConvFlags.INVALID_REPLACE) != 0) {
ecflags |= EConvFlags.UNDEF_REPLACE;