{% macro book_cover(book, title=None, alt=None) -%}
{%- set image_title = book.title if book.title else book.name -%}
{%- set image_title = title if title else image_title -%}
{%- set image_alt = alt if alt else image_title -%}
{% set srcset = book|get_cover_srcset %}
{%- endmacro %}
{% macro series(series, title=None, alt=None) -%}
{%- set image_alt = alt if alt else image_title -%}
{% set srcset = series|get_series_srcset %}
{%- endmacro %}