>>> import albatross
>>> ctx = albatross.SimpleContext('.')
>>> albatross.Template(ctx, '<magic>', '''
... <al-macro name="red">
... <font color="red"><al-usearg></font>
... </al-macro>
... 
... <al-macro name="bold"><b><al-usearg></b></al-macro>
... ''').to_html(ctx)
>>> ctx.flush_content()
>>> albatross.Template(ctx, '<magic>', '''
... <al-expand name="red">more <al-expand name="bold">spam</al-expand> please</al-expand>
... <al-expand name="red"><al-expand name="bold">more spam please</al-expand></al-expand>
... ''').to_html(ctx)
>>> ctx.flush_content()
<font color="red">more <b>spam</b> please</font>
<font color="red"><b>more spam please</b></font>
