Documented grid-span() options do not work

[tannerjfco]

Using Singularity 1.6.2 compiling via libsass fwiw.

Current singularity documentation provides this example under the Isolation Span section:

// Simplifies use of $options for Isolation Output Style
#foo {
  @include grid-span(2, 3, $output-style: 'isolation', $options: 'both');
}
#foo {
  @include isolation-span(2, 3, 'both');
}

Using the grid-span() call as documented above, specifically to set the $options: 'both' parameter, should result in the element receiving the "clear: both;" rule. While I get no error output on this call, I also do not get the desired result. Using the isolation-span() method works as documented, so the issue should be specific to the grid-span() function.