presto-mongodb/src/main/java/io/prestosql/plugin/mongodb/MongoClientConfig.java/MongoClientConfig/setImplicitRowFieldPrefix
class MongoClientConfig:    @Config("mongodb.implicit-row-field-prefix")
    public MongoClientConfig setImplicitRowFieldPrefix(String implicitRowFieldPrefix)
    {
        this.implicitRowFieldPrefix = implicitRowFieldPrefix;
        return this;
    }