<p><a href="http://en.wikipedia.org/wiki/SOLID_(object-oriented_design)">SOLID</a> is an acronym created by <a href="http://en.wikipedia.org/wiki/Robert_Cecil_Martin">Bob
Martin</a> and <a href="https://twitter.com/mfeathers">Michael
Feathers</a> that refers to five fundamental
principles that help engineers write maintainable code. We like to think of these
principles as the foundational elements we use when evaluating the health…</p>

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