* graph.putEdge("bread", "bread");
 * graph.putEdge("chocolate", "peanut butter");
 * graph.putEdge("peanut butter", "jelly");
 *
 * // Building an immutable graph
 * ImmutableGraph<String> immutableGraph =
 *     GraphBuilder.undirected()
 *         .allowsSelfLoops(true)
 *         .<String>immutable()
 *         .putEdge("bread", "bread")
 *         .putEdge("chocolate", "peanut butter")

    checkNotNull(from);
    checkNotNull(to);
    char[] buf = new char[DEFAULT_BUF_SIZE];
    int nRead;
    long total = 0;
    while ((nRead = from.read(buf)) != -1) {
      to.append(buf, 0, nRead);
      total += nRead;
    }
    return total;
  }

  /**
   * Copies all characters between the {@link Reader} and {@link Writer} objects. Does not close or

          try (InputStreamReader reader = new InputStreamReader(byteSource.openStream(), cs)) {
            int nRead = 0;
            while (remaining > 0 && (nRead = reader.read(buffer, bufIndex, remaining)) != -1) {
              bufIndex += nRead;
              remaining -= nRead;
            }
            if (nRead == -1) {
              // we reached EOF
              return new String(buffer, 0, bufIndex);
            }

          try (InputStreamReader reader = new InputStreamReader(byteSource.openStream(), cs)) {
            int nRead = 0;
            while (remaining > 0 && (nRead = reader.read(buffer, bufIndex, remaining)) != -1) {
              bufIndex += nRead;
              remaining -= nRead;
            }
            if (nRead == -1) {
              // we reached EOF
              return new String(buffer, 0, bufIndex);
            }

      frameCallback.onReadMessage(messageFrameBuffer.readByteString())
    }
  }

  /** Read headers and process any control frames until we reach a non-control frame. */
  @Throws(IOException::class)
  private fun readUntilNonControlFrame() {
    while (!receivedCloseFrame) {
      readHeader()
      if (!isControlFrame) {
        break
      }
      readControlFrame()
    }
  }

  /**

            else -> source.read(sink, limit)
          }
        }
      }

      override fun timeout(): Timeout = timeout
    }

    /**
     * Returns a value in [0..maxByteCount] with the number of bytes that can be read from [source]
     * in the current part. If this returns 0 the current part is exhausted; otherwise it has at
     * least one byte left to read.
     */

    eqCount += skipAll('='.code.toByte())
    while (true) {
      if (peek == null) {
        peek = readToken()
        if (skipCommasAndWhitespace()) break // We peeked a scheme name followed by ','.
        eqCount = skipAll('='.code.toByte())
      }
      if (eqCount == 0) break // We peeked a scheme name.
      if (eqCount > 1) return // Unexpected '=' characters.
      if (skipCommasAndWhitespace()) return // Unexpected ','.

 *       block indefinitely or fail if the source creates an infinite reader.
 *   <li><b>Non-destructive:</b> A <i>destructive</i> reader will consume or otherwise alter the
 *       source as they are read from it. A source that provides such readers will not be reusable,
 *       and operations that read from the stream (including {@link #length()}, in some

        b += 2 // We rewound two bytes and then added four.
        break
      } else {
        return null // Wrong delimiter.
      }
    }

    // Read a group, one to four hex digits.
    var value = 0
    groupOffset = i
    while (i < limit) {
      val hexDigit = input[i].parseHexDigit()
      if (hexDigit == -1) break
      value = (value shl 4) + hexDigit
      i++
    }

                removeWaiter(node);
                break long_wait_loop; // jump down to the busy wait loop
              }
            }
          }
          oldHead = waitersField; // re-read and loop.
        } while (oldHead != Waiter.TOMBSTONE);
      }
      // re-read valueField, if we get here then we must have observed a TOMBSTONE while trying to
      // add a waiter.