public static function BitwiseAnd($left_operand, $right_operand)
{
$val1 = BigNumber::Dec2Bin($left_operand);
$val2 = BigNumber::Dec2Bin($right_operand);
$len1 = strlen($val1);
$len2 = strlen($val2);
$maxlen = max($len1, $len2);
for ($i = $len1; $i < $maxlen; $i++) {
$val1 = "0" . $val1;
}
for ($i = $len2; $i < $maxlen; $i++) {
$val2 = "0" . $val2;
}
$result = "";
for ($i = 0; $i < $maxlen; $i++) {
$char = "0";
if ($val1[$i] == "1" && $val2[$i] == "1") {
$char = "1";
}
$result = $result . $char;
}
return BigNumber::Bin2Dec($result);
}