def __call__(self, pattern, pattern_label, pattern_number, master_seed, **params):
raise NotImplementedError<EOL>
'pattern' is the PatternGenerator to be modified
'pattern_label' is the name to be given to this
PatternGenerator, used to select different behaviors
'pattern_number' is an integer value distinguishing between
multiple patterns with the same pattern_label
'master_seed' is to be used for any random number generator
seeds used for this pattern
'params' consists of optional keyword-value pairs to be
provided for subclasses' parameters