DEPRECATION WARNING: Passing a string to call() is deprecated and will be illegal
in Sass 4.0. Use call(get-function("bar")) instead.

  @return call('bar', $predicate);
          ^^^^^^^^^^^^^^^^^^^^^^^
    spec/libsass-issues/issue_1566/input.scss 2:11  foo()
    spec/libsass-issues/issue_1566/input.scss 10:9  root stylesheet
