code: function containsOnlyIdentifiers(node) {
              if (node.type === "Identifier") {
                  return true;
              }
  
              if (node.type === "MemberExpression") {
                  if (node.object.type === "Identifier") {
                      return true;
                  }
                  if (node.object.type === "MemberExpression") {
                      return containsOnlyIdentifiers(node.object);
                  }
              }
  
              return false;
          }
docs: Check to see if a node contains only identifers
  @param {ASTNode} node The node to check
  @returns {boolean} Whether or not the node contains only identifers