This commit introduces a new utility function: 'groupBy'. It is similar in API and result as the underscore method of the same name. X-original-commit: 834a1967161dc537cb2d5543314a062dbac08f9c
This commit introduces a new utility function: 'groupBy'. It is similar in API and result as the underscore method of the same name. X-original-commit: 834a1967161dc537cb2d5543314a062dbac08f9c