presto-hive/src/main/java/io/prestosql/plugin/hive/HiveCoercionRecordCursor.java/IntegerNumberToVarcharCoercer/coerce
class IntegerNumberToVarcharCoercer:        @Override
        public void coerce(RecordCursor delegate, int field)
        {
            setSlice(utf8Slice(String.valueOf(delegate.getLong(field))));
        }