Returns a new slice of this buffer's sub-region starting at the current
{@code readerIndex} and increases the {@code readerIndex} by the size
of the new slice (= {@code length}).
<p>
Also be aware that this method will NOT call {@link #retain()} and so the
reference count will NOT be increased.
@param length the size of the new slice
@return the newly created slice
@throws IndexOutOfBoundsException
if {@code length} is greater than {@code this.readableBytes}
Returns a new slice of this buffer's sub-region starting at the current {@code readerIndex} and increases the {@code readerIndex} by the size of the new slice (= {@code length}). <p> Also be aware that this method will NOT call {@link #retain()} and so the reference count will NOT be increased.
@param length the size of the new slice
@return the newly created slice
@throws IndexOutOfBoundsException if {@code length} is greater than {@code this.readableBytes}