code: function gather (variable, node) {
    if (node.parent) {
      let values = []
      for (let n of Object.values(node.parent.nodes)) {
        if (n.type === 'decl' && n.prop === `$${variable}`) {
          values.push(n.value)
        }
      }
      values.reverse()
      let parentValues = node.parent.parent ? gather(variable, node.parent) : null
      if (parentValues) {
        values = values.concat(parentValues)
      }
      return values
    }
    return null
  }
docs: get the value of a sass variable
  @param {string} variable
  @param {object} node