def __init__(self, chainPath, level = 2, wb = False):
		self.level = level
		self.chain = shelve.open(chainPath, protocol = 2, 
					 writeback = wb)
chainPath is the location of the Markov chain to load; wb is
dataset/ETHPy150Open capnrefsmmat/seuss/Markov.py/MarkovChain.__init__