protected function readColumns($handle)
{
if ($handle === false) {
throw new \RuntimeException("Could not read file '{$this->options['file']}'");
}
$columns = $this->readLine($handle);
if ($columns === false) {
throw new \RuntimeException("Failed to determine csv columns");
}
/**
* Result:
* array(
* 'ColumnName1' => 0,
* 'ColumnName2' => 1
* )
*/
$columns = array_flip($columns);
return $columns;
}