def METHOD_NAME(self):
    """
    Returns size required to create all part files
    """
    size = 0
    for part in self.parts:
        if part is File and part.create is not None:
            size += part.size
    for replica in self.replicas:
        for part in replica:
            if part is File and part.create is not None:
                size += part.size
    return size