val out = Buffer()
    body.writeTo(out)
    assertThat(out.readUtf8()).isEqualTo(expected)
  }

  @Test
  fun addEncoded() {
    val body =
      FormBody
        .Builder()
        .addEncoded("a+=& b", "c+=& d")
        .addEncoded("e+=& f", "g+=& h")
        .addEncoded("%25", "%25")
        .build()
    val expected = "a+%3D%26+b=c+%3D%26+d&e+%3D%26+f=g+%3D%26+h&%25=%25"
    val out = Buffer()

            encodeSet = FORM_ENCODE_SET,
            // Plus is encoded as `%2B`, space is encoded as plus.
            plusIsSpace = false,
            charset = charset,
          )
      }

      fun addEncoded(
        name: String,
        value: String,
      ) = apply {
        names +=
          name.canonicalizeWithCharset(
            encodeSet = FORM_ENCODE_SET,
            alreadyEncoded = true,