code: function renameClassName(ast, oldName, newName) {
    let defNode = null;
    // Find the definition node of the class
    traverse(ast, {
      ClassDeclaration(path) {
        if (path.node.id && path.node.id.name === oldName) {
          defNode = path.node.id;
        }
      }
    });
  
    if (defNode) {
      return identifier.renameIdentifier(ast, oldName, newName, defNode);
    }
    return [];
  }
docs: Rename a es6 class name in a module. Only rename the class definition and its reference in the module.
  It will not find other files to rename reference.
  @param {string} ast - Which module to rename class name.
  @param {string} oldName - The old class name.
  @index {number} newName - The new class name.
  @alias module:refactor.renameClassName
  @example
  // class MyClass {
  //   ...
  // }
  const refactor = require('rekit-core').refactor;
  refactor.renameClassName(file, 'MyClass', 'NewMyClass');
  // => class NewMyClass {
  // =>   ...
  // => }