I retrieve the description field of Event and Task objects. Some descriptions contain copy pasted email and so empty lines exist in the description. I want to replace all empty lines with a single space. Firstly I convert the field content to a string like. 

```
String.valueOf(t.Description).replace('\\s+, ' ')  

```

where t = task. I have tested many cases but does not seem to work. how can I do that? Thank you in advance!