>>> import albatross
>>> ctx = albatross.SimpleContext('.')
>>> albatross.Template(ctx, '<magic>', '''
... <al-for iter="i" expr="range(15)" whitespace="indent">
...  <al-value expr="i.value()">
... </al-for whitespace>
... ''').to_html(ctx)
>>> ctx.flush_content()
 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
