code: function isClassConstructor(node) {
      return node.type === "FunctionExpression" &&
          node.parent &&
          node.parent.type === "MethodDefinition" &&
          node.parent.kind === "constructor";
  }
docs: Checks whether a given node is a `constructor` method in an ES6 class
  @param {ASTNode} node A node to check
  @returns {boolean} `true` if the node is a `constructor` method