handler

1. One who handles something (especially manually) or someone. · The handler of a weapon gets a symbolic sensation of deadly power.
2. A controller, trainer, someone who handles a specified thing, animal or person (especially a prizefighter). · The spy's handler told him to approach the subject by posing as a dog handler.
3. An advisor or manager providing guidance to a person occupying public office or a prominent position. · The governor received guidance on how to best disseminate key information to the public from her handler.
4. A subroutine that handles a particular situation such as an event or exception.

Plural handlers