Sets the {@code readerIndex} and {@code writerIndex} of this buffer to
{@code 0}.
This method is identical to {@link #setIndex(int, int) setIndex(0, 0)}.
<p>
Please note that the behavior of this method is different
from that of NIO buffer, which sets the {@code limit} to
the {@code capacity} of the buffer.
Sets the {@code readerIndex} and {@code writerIndex} of this buffer to {@code 0}. This method is identical to {@link #setIndex(int, int) setIndex(0, 0)}. <p> Please note that the behavior of this method is different from that of NIO buffer, which sets the {@code limit} to the {@code capacity} of the buffer.