/**
 * Returns true if the body in question probably contains human readable text. Uses a small
 * sample of code points to detect unicode control characters commonly used in binary file
 * signatures.
 */
fun Buffer.isProbablyUtf8(): Boolean {
  try {
    val prefix = Buffer()
    val byteCount = size.coerceAtMost(64)
    copyTo(prefix, 0, byteCount)
    for (i in 0 until 16) {
      if (prefix.exhausted()) {
        break
      }

import assertk.assertions.isTrue
import okhttp3.logging.internal.isProbablyUtf8
import okio.Buffer
import org.junit.jupiter.api.Test

class IsProbablyUtf8Test {
  @Test fun isProbablyUtf8() {
    assertThat(Buffer().isProbablyUtf8()).isTrue()
    assertThat(Buffer().writeUtf8("abc").isProbablyUtf8()).isTrue()
    assertThat(Buffer().writeUtf8("new\r\nlines").isProbablyUtf8()).isTrue()