// Context handle is modified by the server (typically zeroed out)
        if (contextHandle == null) {
            contextHandle = new byte[20];
        }
        buf.readOctetArray(contextHandle, 0, 20);
    }

    /**
     * Checks if the context handle has been invalidated (all zeros).
     * A successful unregistration typically results in a zeroed context handle.
     *

        // Decode output parameters for WitnessRegister

        // Context handle (20 bytes)
        if (contextHandle == null) {
            contextHandle = new byte[20];
        }
        buf.readOctetArray(contextHandle, 0, 20);
    }

    /**
     * Encodes a wide string pointer in NDR format.
     *
     * @param buf the NDR buffer
     * @param str the string to encode (can be null)

        byte[] sourceData = { 0x10, 0x11, 0x12, 0x13, 0x14 };
        System.arraycopy(sourceData, 0, buffer, 0, sourceData.length);

        byte[] destData = new byte[5];
        ndrBuffer.readOctetArray(destData, 0, sourceData.length);

        assertEquals(sourceData.length, ndrBuffer.getIndex());
        assertEquals(sourceData.length, ndrBuffer.getLength()); // Length is updated on read too

     * Reads an octet array from the buffer.
     *
     * @param b the byte array to read into
     * @param i the starting index in the array
     * @param l the number of bytes to read
     */
    public void readOctetArray(final byte[] b, final int i, final int l) {
        System.arraycopy(buf, index, b, i, l);
        advance(l);
    }

    /**
     * Returns the length of data in the buffer.
     *

     * Reads an octet array from the buffer.
     *
     * @param b the byte array to read into
     * @param i the starting index in the array
     * @param l the number of bytes to read
     */
    public void readOctetArray(final byte[] b, final int i, final int l) {
        System.arraycopy(this.buf, this.index, b, i, l);
        advance(l);
    }

    /**
     * Returns the length of data in the buffer.
     *

            return "";
        }

        // Read wide string data (UTF-16LE)
        int byteCount = (actualCount - 1) * 2; // Exclude null terminator
        byte[] wideBytes = new byte[byteCount];
        buf.readOctetArray(wideBytes, 0, byteCount);

        // Skip null terminator
        buf.dec_ndr_short();

        // Skip padding
        int padding = (4 - ((byteCount + 2) % 4)) % 4;