prot.writeString("hello world!");
prot.writeFieldEnd();
prot.writeFieldBegin(new TField());
prot.writeMapBegin(new TMap());
prot.writeString("key1");
prot.writeString("val1");
prot.writeString("key2");
prot.writeString("val2");
prot.writeString("key3");
prot.writeString("val3");