filters applied in wrong order

[fkv1]

According to the documentation:

To apply more than one filter, separate them by a comma:
${" some value " | h,trim}
The HTML escaping function is applied first, the “trim” function second.

But when I do:

<%
  def keep_spaces(p_s):
    return p_s.replace(' ','&nbsp;')
%>
${x |h, keep_spaces}

it transforms " ABC" into

  ABC

instead of just

  ABC