private var keyAlgorithm: String? = null
    private var keySize: Int = 0

    init {
      ecdsa256()
    }

    /**
     * Sets the certificate to be valid in ```[notBefore..notAfter]```. Both endpoints are specified
     * in the format of [System.currentTimeMillis]. Specify -1L for both values to use the default
     * interval, 24 hours starting when the certificate is created.
     */
    fun validityInterval(

=== ":material-language-kotlin: Kotlin"
    ```kotlin
      private val client = OkHttpClient()

      fun run() {
        // Use the imgur image upload API as documented at https://api.imgur.com/endpoints/image
        val requestBody = MultipartBody.Builder()
            .setType(MultipartBody.FORM)
            .addFormDataPart("title", "Square Logo")
            .addFormDataPart("image", "logo-square.png",