def extract_string_selectors(selector_array)
      selector_array.reject { |item| item.is_a? Sass::Script::Node }
                    .join
                    .split
    end
def extract_string_selectors(selector_array)
      selector_array.reject { |item| item.is_a? Sass::Script::Node }
                    .join
                    .split
    end
Given a selector array which is a list of strings with Sass::Script::Nodes
 interspersed within them, return an array of strings representing those
 selectors with the Sass::Script::Nodes removed (i.e., ignoring
 interpolation). For example:

 .selector-one, .selector-#{$var}-two

 becomes:

 .selector-one, .selector--two

 This is useful for lints that wish to ignore interpolation, since
 interpolation can't be resolved at this step.