private static byte[] buildErrorBody(int errorContextCount, int bc, byte[] errorData) {
        int bodyLen = 8 + bc; // 8 bytes fixed + variable data
        byte[] buf = new byte[bodyLen];
        SMBUtil.writeInt2(9, buf, 0); // structureSize
        buf[2] = (byte) errorContextCount; // ErrorContextCount
        // one reserved byte at position 3
        SMBUtil.writeInt4(bc, buf, 4); // ByteCount

        int bodyStart = headerStart + Smb2Constants.SMB2_HEADER_LENGTH;
        // Error response structure: size(2)=9, errorContextCount(1), reserved(1), bc(4), errorData(bc)
        SMBUtil.writeInt2(9, buf, bodyStart);
        buf[bodyStart + 2] = 0x02; // errorContextCount
        buf[bodyStart + 3] = 0x00; // reserved
        int bc = 4;
        SMBUtil.writeInt4(bc, buf, bodyStart + 4);

        return this.errorData;
    }

    /**
     * Gets the error context count for this message.
     *
     * @return the errorContextCount
     */
    public final byte getErrorContextCount() {
        return this.errorContextCount;
    }

    /**
     * Gets the header start position for this message.
     *
     * @return the headerStart
     */