Project comparisons allow you to view any selection of projects side by side just like they're shown on regular categories or in search results. You can try out an example or start yourself by adding a library to the comparison via the input below. You can also easily share your current comparison with others by sending the URL of the current page.
The Preconditions library provides a simple set of methods for checking arguments being passed into a method. Instead of writing custom checks and raising exceptions directly in your code you can use Preconditions to verify basic properties of your arguments (not-nil, satisfying a boolean expression, being of a certain type/duck-type) and raise the appropriate exception for you.