The docstring is now quite important to know what the
params are (they are no longer as obvious due to the
decider addition) so add a useful docstring to that
method.
This also fixes how the targeted flow add was not passing
allow **kwargs as it should have been and removes the
duplicated docstrings that are in the child class (the
parent class docstrings are just fine).
Change-Id: Idacb7ee9f652fab4bdc762c1b49d7523e46e9a7b