Line 704 should be rewritten as :
```
if (delimiter === 'TAB') {
    mimeType = 'text/tab-separated-values';
} else if (delimiter === 'SPACE') {
    mimeType = ''text/plain';
} else {
    mimeType = ''text/csv';
}
```

Currently, the logic is: 
```
if (delimiter === 'TAB') {
    mimeType = 'text/tab-separated-values';
} else {
    if (delimiter === 'SPACE') {
        mimeType = ''text/plain';
    } else {
        mimeType = ''text/csv';
    }
}
```

Confusing.