import hashlib


def get_hash (strings, prefix=None, digest_size=10):
    """
    construct a unique identifier from a collection of strings
    """
    m = hashlib.blake2b(digest_size=digest_size)
    
    for elem in sorted(map(lambda x: x.encode("utf-8").lower().strip(), strings)):
        m.update(elem)

    if prefix:
        id = prefix + m.hexdigest()
    else:
        id = m.hexdigest()

    return id