public void copyTo(final byte[] target, final int sourceOffset,
            final int targetOffset,
            final int size)
    {
        System.arraycopy(bytes, sourceOffset, target, targetOffset, size);
    }
Copies bytes into a buffer.

@param target
           buffer to copy into
@param sourceOffset
           offset within these bytes
@param targetOffset
           offset within the target buffer
@param size
           number of bytes to copy
protostuff-api/src/main/java/io/protostuff/ByteString.java