'Set the user partitions for a particular scheme.
Preserves partitions associated with other schemes.
Arguments:
scheme (object): The user partition scheme.
Returns:
list of `UserPartition`'

def set_user_partitions_for_scheme(self, partitions, scheme):

    other_partitions = [p for p in self.user_partitions if (p.scheme != scheme)]
    self.user_partitions = (other_partitions + partitions)
