'Initialize any data structures or variables needed for keeping track
of the tasty bits we find in the log we are parsing.'

def __init__(self, option_string=None):

    self.metrics = {}
    if option_string:
        options = option_string.split('    ')
    else:
        options = []
    optparser = optparse.OptionParser()
    optparser.add_option('--key-separator', '-k', dest='key_separator', default='.', help="Key    separator    for    flattened    json    object    key    name.    Default:    '.'")
    (opts, args) = optparser.parse_args(args=options)
    self.key_separator = opts.key_separator
