private constructor()

in packages/misc/css-var-utils/src/define-css-var.ts [127:131]

• 4 lines of code
• 2 McCabe index (conditional complexity)

  private constructor(_vars: CssVars, key: typeof constructor_key) {
    // 调用构造函数只允许被内部调用
    if (key !== constructor_key) throw new Error(constructor_key)
    this._vars = _vars
  }