'Return an Origin object pointing to an absolute path in each directory
in template_dirs. For security reasons, if a path doesn\'t lie inside
one of the template_dirs it is excluded from the result set.'

def get_template_sources(self, template_name):

    for template_dir in self.get_dirs():
        try:
            name = safe_join(template_dir, template_name)
        except SuspiciousFileOperation:
            continue
        (yield Origin(name=name, template_name=template_name, loader=self))
