Initializes this exemption mechanism with a key and a set of algorithm parameters.

If this exemption mechanism requires any algorithm parameters and params is null, the underlying exemption mechanism implementation is supposed to generate the required parameters itself (using provider-specific default values); in the case that algorithm parameters must be specified by the caller, an InvalidAlgorithmParameterException is raised.

Parameters:

key		the key for this exemption mechanism
params		the algorithm parameters

Exceptions:

InvalidKeyException		if the given key is inappropriate for this exemption mechanism.
InvalidAlgorithmParameterException		if the given algorithm parameters are inappropriate for this exemption mechanism.
ExemptionMechanismException		if problem(s) encountered in the process of initializing.