# minBy

Returns the elements in an observable sequence with the minimum key value according to the specified comparer.

## Arguments

1. `keySelector` *(`Function`)*: Key selector function.
2. `[comparer]` *(`Function`)*:  Comparer used to compare elements.

## Returns

*(`Observable`)*: An observable sequence containing a list of zero or more elements that have a minimum key value.

## Example
