Don't inherit from DelegateClass for performance.
Memoize ruby version information for performance.
Optimize hash iteration.
Don't call require inside commonly called methods.
Storing node names against the class results in a marginal speedup.
Memoize these values against the same class
Only dup the number when it has an original value for performance.
Use class storage for this cache instead of a hash for performance
Avoid Proc allocations for performance
Speedup lcs computation by avoiding explicit blocks.
Fix warnings and errors in OrderedHash and NormalizedMap.
Style nit.
Fix test failure.
Fewer lines
Don't run style checks when testing a specific test.
A generic method for issuing API deprecation warnings.
Calculate visitor names on Node inheritance.
Move the require and the related method closer together.
Code comments for clarity
Make Sass::Util methods invokable only on the module itself.