Extracts data from a text file with fields delimited by a fixed number of characters.
$etl->extract('fixed_width', 'path/to/file.txt', $options);
Columns that will be extracted.
$options = ['columns' => [
'id' => [0, 5], // Start position is 0 and length is 5.
'name' => [5, 40], // Start position is 5 and length is 40.
]];