assertEquals(-1, reader.read());
    assertEquals(-1, reader.read(new char[10], 0, 10));
    assertEquals(-1, reader.read(CharBuffer.allocate(10)));
    assertEquals(0, reader.skip(10));
  }

  private static String readFully(CharSequenceReader reader) throws IOException {
    StringBuilder builder = new StringBuilder();
    int read;
    while ((read = reader.read()) != -1) {
      builder.append((char) read);

                WebSocket.

                Read more about it in the
                [FastAPI docs for WebSockets](https://fastapi.tiangolo.com/advanced/websockets/).
                """
            ),
        ] = None,
    ) -> Callable[[DecoratedCallable], DecoratedCallable]:
        """
        Decorate a WebSocket function.

        Read more about it in the

    assertEquals(0, ticker.read());
    assertEquals(10, ticker.read());
    assertEquals(20, ticker.read());
  }

  public void testAutoIncrementStep_millis() {
    FakeTicker ticker = new FakeTicker().setAutoIncrementStep(1, MILLISECONDS);
    assertEquals(0, ticker.read());
    assertEquals(1000000, ticker.read());
    assertEquals(2000000, ticker.read());
  }

    // The stream reports no bytes... importantly, it doesn't read the byte at index 5 when it
    // should be reading the byte at index 10.
    // We could use a custom InputStream instead to make the read start at index 10, but since this
    // is a racy situation anyway, this behavior seems reasonable.
    assertEquals(-1, in.read());
  }

  private static class AppendableByteSource extends ByteSource {

    assertEquals(2, lin.available());
    int read = lin.read();
    assertEquals(big[0], read);
    assertEquals(1, lin.available());
    read = lin.read();
    assertEquals(big[1], read);
    assertEquals(0, lin.available());
    read = lin.read();
    assertEquals(-1, read);

    lin.reset();
    byte[] small = new byte[5];
    read = lin.read(small);
    assertEquals(2, read);
    assertEquals(big[0], small[0]);

    assertEquals(0, ticker.read());
    assertEquals(10, ticker.read());
    assertEquals(20, ticker.read());
  }

  public void testAutoIncrementStep_millis() {
    FakeTicker ticker = new FakeTicker().setAutoIncrementStep(1, MILLISECONDS);
    assertEquals(0, ticker.read());
    assertEquals(1000000, ticker.read());
    assertEquals(2000000, ticker.read());
  }

    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());
  }

  public void testOpenBufferedStream() throws IOException {

// Use it with other programs, like
$ echo "Hello $Env:MY_NAME"

Hello Wade Wilson
```

</div>

////

## Read env vars in Python { #read-env-vars-in-python }

You could also create environment variables **outside** of Python, in the terminal (or with any other method), and then **read them in Python**.

For example you could have a file `main.py` with:

```Python hl_lines="3"
import os

            Read more about it in the
            [FastAPI docs about Query parameters](https://fastapi.tiangolo.com/tutorial/query-params-str-validations/#declare-more-metadata)
            """
        ),
    ] = None,
    description: Annotated[
        str | None,
        Doc(
            """
            Human-readable description.

            Read more about it in the

    assertEquals(expected.charAt(0), joinedReader.read());
    CharStreams.skipFully(joinedReader, 1);
    assertEquals(expected.charAt(2), joinedReader.read());
    CharStreams.skipFully(joinedReader, 4);
    assertEquals(expected.charAt(7), joinedReader.read());
    CharStreams.skipFully(joinedReader, 1);
    assertEquals(expected.charAt(9), joinedReader.read());
    assertEquals(-1, joinedReader.read());
  }