create split method to the factory that changes the behavior of build, and output two or more datasets
def split(rates=[0.3,0.7])
'''Defines some sizes to take from the dataset field to create other instances of dataset with less data''
poss = trans(rates)
multiple rates are defined, for example for 10-fold crossvalidation 10*[0.1]
create split method to the factory that changes the behavior of build, and output two or more datasets
multiple rates are defined, for example for 10-fold crossvalidation 10*[0.1]