presto-hive/src/main/java/io/prestosql/plugin/hive/HivePageSource.java/ListCoercer/ListCoercer
class ListCoercer:        public ListCoercer(TypeManager typeManager, HiveType fromHiveType, HiveType toHiveType)
        {
            requireNonNull(typeManager, "typeManage is null");
            requireNonNull(fromHiveType, "fromHiveType is null");
            requireNonNull(toHiveType, "toHiveType is null");
            HiveType fromElementHiveType = HiveType.valueOf(((ListTypeInfo) fromHiveType.getTypeInfo()).getListElementTypeInfo().getTypeName());
            HiveType toElementHiveType = HiveType.valueOf(((ListTypeInfo) toHiveType.getTypeInfo()).getListElementTypeInfo().getTypeName());
            this.elementCoercer = fromElementHiveType.equals(toElementHiveType) ? null : createCoercer(typeManager, fromElementHiveType, toElementHiveType);
        }