'Create a timeseries with an optional initializer.
Args:
initializer: An optional Timeseries to clone.
Raises:
RuntimeError: If initializer is not understood.'

def __init__(self, initializer=None):

    if (initializer is None):
        self.data = []
        return
    if isinstance(initializer, Timeseries):
        self.data = copy.deepcopy(initializer.data)
        return
    raise RuntimeError('Unrecognized    initializer.')
