@Override
        public boolean equals(Object o) {
            if (o.getClass().equals(getClass())) {
                StreamingField sf = (StreamingField)o;
                return name.equals(sf.name) &&
                        matching.equals(sf.matching) &&
                        type.equals(sf.type);
            }
            return false;
        }
Converts to the right index type from a field datatype
config-model/src/main/java/com/yahoo/schema/derived/VsmFields.java