Using 3rd party script in jquery plugin

What is the best way to include a 3rd 开发者_开发百科party script for use in a jquery (or jquery ui) plugin?

For example, I'm writing a jQuery UI plugin that makes heavy use of dates, the in built javascript date object is not brilliant so I want to use date.js, how should I include it for use and deal with dependency issues?

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As for me the simplest way just use it and describe depedency in header comment or install guide. There is no obvious/standard ways to include dependecies from JS code and IMHO you shouldn't decide for user how to check and inject dependency.