code: function validate(awaitNode) {
              if (awaitNode.type === "ForOfStatement" && !awaitNode.await) {
                  return;
              }
  
              let node = awaitNode;
              let parent = node.parent;
  
              while (parent && !isBoundary(parent)) {
                  if (isLooped(node, parent)) {
                      context.report({
                          node: awaitNode,
                          messageId: "unexpectedAwait"
                      });
                      return;
                  }
                  node = parent;
                  parent = parent.parent;
              }
          }
docs: Validate an await expression.
  @param {ASTNode} awaitNode An AwaitExpression or ForOfStatement node to validate.
  @returns {void}