src/Builder/Syntax/AbstractSetWriter.php
protected function abstractWrite(QueryPartInterface $setClass, $setOperation, $glue)
    {
        $selects = [];

        foreach ($setClass->$setOperation() as $select) {
            $selects[] = $this->writer->write($select, false);
        }

        return \implode("\n".$glue."\n", $selects);
    }
protected function abstractWrite(QueryPartInterface $setClass, $setOperation, $glue)
    {
        $selects = [];

        foreach ($setClass->$setOperation() as $select) {
            $selects[] = $this->writer->write($select, false);
        }

        return \implode("\n".$glue."\n", $selects);
    }
@param QueryPartInterface $setClass
@param string             $setOperation
@param $glue

@return string