function getDirective(node, name, argument) {
  return (
    node.startTag.attributes.find(
      /**
       * @param {VAttribute | VDirective} node
       * @returns {node is VDirective}
       */
      (node) =>
        node.directive &&
        node.key.name.name === name &&
        (argument === undefined ||
          (node.key.argument &&
            node.key.argument.type === 'VIdentifier' &&
            node.key.argument.name) === argument)
    ) || null
  )
}
Get the directive which has the given name.
@param {VElement} node The start tag node to check.
@param {string} name The directive name to check.
@param {string} [argument] The directive argument to check.
@returns {VDirective | null} The found directive.