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ext 

        # String.ext

(from gem rake-13.0.6)
---
    ext(newext="")

---

Replace the file extension with `newext`.  If there is no extension on
the string, append the new extension to the end.  If the new extension
is not given, or is the empty string, remove any existing extension.

`ext` is a user added method for the String class.

This String extension comes from Rake

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