I have the following paragraph:

```
1 sometexthere  
2     indented text
3     indented text
4     indented text

```

I would like to use vim's search and replace command to add some text right before indented text. For example:

```
1 sometexthere  
2     test: indented text
3     test: indented text
4     test: indented text

```

Is there a way to use vim's search and replace syntax to achieve the following results? I have tried commands like
`2,4s/^/test: /` but still can't figure out a way to strip off the whitespace.