@spec perform(atom(), User.t(), list()) :: list() | {:error, any()}
def perform(:blocks_import, %User{} = blocker, blocked_identifiers)
when is_list(blocked_identifiers) do
@spec perform(atom(), User.t(), list()) :: list() | {:error, any()}
def perform(:blocks_import, %User{} = blocker, blocked_identifiers)
when is_list(blocked_identifiers) do