public void resolve() {
        RankType rankType = null;
        if (fields.size() > 0) {
            boolean first = true;
            for (SDField field : fields) {
                if (first) {
                    rankType = fields.get(0).getRankType();
                    first = false;
                } else if (!field.getRankType().equals(rankType)) {
                    deployLogger.logApplicationPackage(Level.WARNING, "In field '" + field.getName() + "' " +
                            field.getRankType() + " for index '" + indexName +
                            "' conflicts with " + rankType +
                            " defined for the same index in field '" +
                            field.getName() + "'. Using " +
                            rankType + ".");
                    field.setRankType(rankType);
                }
            }
        }
    }
Checks if fields have defined different rank types for the same
index (typically in a fieldset statement), and if they have
output a warning and use the first ranktype.

@author hmusum
config-model/src/main/java/com/yahoo/schema/processing/multifieldresolver/RankTypeResolver.java