import string
import random


def unique_id(prefix, size=16, chars=string.ascii_lowercase + string.digits):
    """Generates a unique ID of the form "prefix-..." (default: "prefix-[a-z0-9]{size}")

    Args:
        prefix: The prefix that is prepended to the ID.
        size: The length of the ID (excluding prefix)
        chars: The character list from which the ID characters are drawn.

    Returns:
        The generated ID.
    """
    return f'{prefix}-{"".join(random.choice(chars) for _ in range(size))}'