static void copy(Field<?> from, Field<?> to)
    {
        to.name = from.name;
        to.number = from.number;
        to.modifier = from.modifier;
        to.addAnnotations(from.annotations, true);
        to.standardOptions.putAll(from.standardOptions);
        to.extraOptions.putAll(from.extraOptions);
        to.docs.addAll(from.docs);
    }
Represents the message defined in the {@link Proto}.

@author David Yu
@created Dec 19, 2009
protostuff-parser/src/main/java/io/protostuff/parser/Message.java