@NotNull
    private String bytesToPostgresHex (byte[] bytes) {
        if (bytes == null) return "";

        char[] hexChars = new char[bytes.length * 2];
        for (int j = 0; j < bytes.length; j++) {
            int v = bytes[j] & 0xFF;
            hexChars[j * 2] = hexArray[v >>> 4];
            hexChars[j * 2 + 1] = hexArray[v & 0x0F];
        }
        return  "\\\\x" + new String(hexChars);
    }
******************************************************************************************
From BLOB to Hexadecimal String for Postgres Copy
@return string representation of blob
*******************************************************************************************
src/main/java/org/replicadb/manager/PostgresqlManager.java