def get_epoch_price_multiplier( block_height, namespace_id, units ):
    """
    what's the name price multiplier for this epoch?
    Not all epochs have one---if this epoch has BLOCKSTACK_INT_DIVISION set, use
    get_epoch_price_divisor() instead.
    """
    try:
        assert units in [TOKEN_TYPE_STACKS, 'BTC'], 'Unknown units {}'.format(units)
    except AssertionError as ae:
        log.exception(ae)
        log.error("FATAL: No such units {}".format(units))
        os.abort()

    multiplier = 'PRICE_MULTIPLIER' if units == 'BTC' else 'PRICE_MULTIPLIER_STACKS'

    epoch_config = get_epoch_config( block_height )
    m = None

    if epoch_config['namespaces'].has_key(namespace_id):
        m = epoch_config['namespaces'][namespace_id][multiplier]
    else:
        m = epoch_config['namespaces']['*'][multiplier]

    try:
        assert m is not None
    except AssertionError as ae:
        log.exception(ae)
        log.error("FATAL: Tried to get a price multiplier in an epoch without price multipliers!")
        os.abort()

    return m
what's the name price multiplier for this epoch?
    Not all epochs have one---if this epoch has BLOCKSTACK_INT_DIVISION set, use
    get_epoch_price_divisor() instead.