// The most common case is that from is a Reader (like InputStreamReader or StringReader) so
    // take advantage of that.
    if (from instanceof Reader) {
      // optimize for common output types which are optimized to deal with char[]
      if (to instanceof StringBuilder) {
        return copyReaderToBuilder((Reader) from, (StringBuilder) to);
      } else {
        return copyReaderToWriter((Reader) from, asWriter(to));
      }
    }

       * about one-sixth of them need cloning when a table doubles. The nodes they replace will be
       * garbage collectable as soon as they are no longer referenced by any reader thread that may
       * be in the midst of traversing table right now.
       */

      int newCount = count;
      AtomicReferenceArray<E> newTable = newEntryArray(oldCapacity << 1);

  static boolean isNullable(Invokable<?, ?> invokable) {
    return NULLNESS_ANNOTATION_READER.isNullable(invokable);
  }

  static boolean isNullable(Parameter param) {
    return NULLNESS_ANNOTATION_READER.isNullable(param);
  }

  private static boolean containsNullable(Annotation[] annotations) {
    for (Annotation annotation : annotations) {

 * @author Colin Decker
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public final class Files {

  private Files() {}

  /**
   * Returns a buffered reader that reads from a file using the given character set.
   *
   * <p><b>{@link java.nio.file.Path} equivalent:</b> {@link
   * java.nio.file.Files#newBufferedReader(java.nio.file.Path, Charset)}.
   *

  }

  public void testOpenStream() throws IOException {
    Reader reader = source.openStream();

    StringWriter writer = new StringWriter();
    char[] buf = new char[64];
    int read;
    while ((read = reader.read(buf)) != -1) {
      writer.write(buf, 0, read);
    }
    reader.close();
    writer.close();

    assertExpectedString(writer.toString());
  }

      @Override
      String read(ByteSource byteSource, Charset cs) throws IOException {
        StringBuilder sb = new StringBuilder();
        try (InputStreamReader reader = new InputStreamReader(byteSource.openStream(), cs)) {
          CharStreams.copy(reader, sb);
        }
        return sb.toString();
      }
    },
    // It really seems like this should be faster than TO_BYTE_ARRAY_NEW_STRING.  But it just isn't

      @Override
      String read(ByteSource byteSource, Charset cs) throws IOException {
        StringBuilder sb = new StringBuilder();
        try (InputStreamReader reader = new InputStreamReader(byteSource.openStream(), cs)) {
          CharStreams.copy(reader, sb);
        }
        return sb.toString();
      }
    },
    // It really seems like this should be faster than TO_BYTE_ARRAY_NEW_STRING.  But it just isn't

    sink.write(STRING);

    assertTrue(sink.wasStreamOpened() && sink.wasStreamClosed());
    assertEquals(STRING, sink.getString());
  }

  public void testWriteFrom_reader() throws IOException {
    StringReader reader = new StringReader(STRING);
    sink.writeFrom(reader);

    assertTrue(sink.wasStreamOpened() && sink.wasStreamClosed());
    assertEquals(STRING, sink.getString());
  }

import java.nio.CharBuffer;
import java.util.Random;

/**
 * Benchmarks for {@link CharStreams#copy}.
 *
 * <p>{@link CharStreams#copy} has type specific optimizations for various common Appendable and
 * Reader implementations, this compares the performance of the different options.
 */
// These benchmarks allocate a lot of data so use a large heap
@VmOptions({"-Xms12g", "-Xmx12g", "-d64"})
public class CharStreamsCopyBenchmark {

import java.nio.CharBuffer;
import java.util.Random;

/**
 * Benchmarks for {@link CharStreams#copy}.
 *
 * <p>{@link CharStreams#copy} has type specific optimizations for various common Appendable and
 * Reader implementations, this compares the performance of the different options.
 */
// These benchmarks allocate a lot of data so use a large heap
@VmOptions({"-Xms12g", "-Xmx12g", "-d64"})
public class CharStreamsCopyBenchmark {