Uncaught TypeError: Cannot read property 'prototype' of undefined

[Enter steps to reproduce below:]
1. ...
2. ...

**Atom Version**: 0.187.0
**System**: Mac OS X 10.10.3
**Thrown From**: [project-palette-finder](https://github.com/abe33/atom-project-palette-finder) package, v2.4.17
### Stack Trace

Uncaught TypeError: Cannot read property 'prototype' of undefined

```
At /Users/saket/.atom/packages/project-palette-finder/lib/palette-provider.coffee:3

TypeError: Cannot read property 'prototype' of undefined
at __extends (/Users/saket/.atom/packages/project-palette-finder/lib/palette-provider.coffee:1:1)
at /Users/saket/.atom/packages/project-palette-finder/lib/palette-provider.coffee:5:5
at module.exports (/Users/saket/.atom/packages/project-palette-finder/lib/palette-provider.coffee:55:7)
at /Users/saket/.atom/packages/project-palette-finder/lib/project-palette-finder.coffee:71:13

```
### Commands

```
2x -36:09.3 deprecation-cop:view (atom-workspace.workspace.scrollbars-visible-always.theme-ruby-robot-theme.theme-seti-ui)
-35:42.1 core:paste (atom-text-editor.editor)
-35:38.6 core:save (atom-text-editor.editor)
20x -35:03.7 core:backspace (atom-text-editor.editor.mini)
20x -34:11.0 core:move-right (atom-text-editor.editor.mini)
4x -34:09.7 core:backspace (atom-text-editor.editor.mini)
2x -34:06.8 core:confirm (atom-text-editor.editor.mini)
-33:36.9 core:save (atom-text-editor.editor)
6x -33:28.6 core:backspace (atom-text-editor.editor)
2x -33:04.4 core:save (atom-text-editor.editor)
3x -32:54.0 tree-view:toggle (atom-text-editor.editor)
-32:46.3 core:backspace (atom-text-editor.editor)
-32:44.9 tree-view:toggle (atom-text-editor.editor)
4x -32:36.9 core:backspace (atom-text-editor.editor)
-32:27.5 core:move-right (atom-text-editor.editor)
37x -32:27.2 core:backspace (atom-text-editor.editor)
```
### Config

``` json
{
"core": {
"themes": [
"seti-ui",
"ruby-robot-theme"
]
}
}
```
### Installed Packages

``` coffee
# User
atom-color-highlight, v3.0.9
compass, v0.9.1
drupal, v1.8.0
drupal-info-file, v1.5.1
emmet, v2.3.10
language-swig, v0.1.1
language-twig, v1.6.1
linter-scss-lint, v1.0.4
project-palette-finder, v2.4.17
ruby-robot-theme, v1.0.0
sassbeautify, v0.2.0
seti-ui, v0.3.6
wakatime, v2.0.1

# Dev
No dev packages
```

The error occurs in /lib/palette-provider.coffee at line 3, where __extends tries to access 'prototype' of an undefined value. Examine the class inheritance in that file, likely a missing import or undefined parent class. Check the Atom API for the correct base class. Run the package in Atom's dev mode to reproduce the error.

Written by the indexing model from the issue text.