assertThat(buffer.isProbablyUtf8(100L)).isTrue()
    assertThat(buffer.readUtf8()).isEqualTo("hello ".repeat(1024))
  }

  /** Confirm [isProbablyUtf8] doesn't attempt to read the entire stream. */
  @Test fun doesNotReadEntireSource() {
    val unlimitedSource =
      object : Source {
        override fun read(
          sink: Buffer,
          byteCount: Long,
        ): Long {
          sink.writeUtf8("a".repeat(byteCount.toInt()))