protected function collectInvalidColumns(array $row)
    {
        $invalidColumns = [];

        foreach ($row as $column) {
            if (!$this->isColumnName($column)) {
                $invalidColumns[] = $column;
            }
        }
        return $invalidColumns;
    }
protected function collectInvalidColumns(array $row)
    {
        $invalidColumns = [];

        foreach ($row as $column) {
            if (!$this->isColumnName($column)) {
                $invalidColumns[] = $column;
            }
        }
        return $invalidColumns;
    }
protected function collectInvalidColumns ( array $ row ) { $ invalidColumns = [ ] ; foreach ( $ row as $ column ) { if ( ! $ this -> isColumnName ( $ column ) ) { $ invalidColumns [ ] = $ column ; } } return $ invalidColumns ; }
Collects invalid column names for better error messages

@param array $row

@return array
Collects invalid column names for better error messages