# multicast

Multicasts the source sequence notifications through an instantiated subject into all uses of the sequence within a selector function. Each subscription to the resulting sequence causes a separate multicast invocation, exposing the sequence resulting from the selector function's invocation. For specializations with fixed subject types, see `publish`, `share`, `publishValue`, `shareValue`, `publishLast`, `replay`, and `shareReplay`.

## Arguments

1. `subjectSelector` _(`Function`)_:  Factory function to create an intermediate subject through which the source sequence's elements will be multicast to the selector function.
2. `subject` _(Subject)_: Subject to push source elements into.
3. `[selector]` _(`Function`)_: Optional selector function which can use the multicasted source sequence subject to the policies enforced by the created subject. Specified only if `subjectSelector` is provided.

## Returns

_(`Observable`)_: An observable sequence that contains the elements of a sequence produced by multicasting the source sequence within a selector function.

## Example
