What is the process to incorporate multiple inheritance using OpenZeppelin upgradeable contracts?

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To incorporate multiple inheritance using OpenZeppelin upgradeable contracts, you can follow the below steps:

1. Create a new contract that inherits from multiple contracts that you want to combine.
2. Use the "is" keyword to indicate that your new contract is an extension of the other contracts.
3. Use the "WithAdminRole" or other role-related contracts you want to use as a base.
4. Use the "Initializable" contract from OpenZeppelin to ensure that the constructor is only called once during contract deployment, even if the contract is upgraded.
5. Use the OpenZeppelin "Initializable" modifier for each constructor that your new contract extends.
6. Use the "super" keyword to call the parent constructors.

Here's an example:

import "@openzeppelin/contracts-upgradeable/access/AccessControlUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";

contract MyNewContract is Initializable, OwnableUpgradeable, AccessControlUpgradeable {
    bytes32 public constant ADMIN_ROLE = keccak256("ADMIN_ROLE");

    function initialize() initializer public {
        __Ownable_init();
        __AccessControl_init();
        _setupRole(DEFAULT_ADMIN_ROLE, msg.sender);
        _setupRole(ADMIN_ROLE, msg.sender);
    }
}

In the example above, "MyNewContract" is inheriting from "OwnableUpgradeable", "AccessControlUpgradeable", and "Initializable". The constant "ADMIN_ROLE" is also declared using the keccak256 hashing algorithm. Finally, the constructor "initialize()" is created using the "initializer" modifier from OpenZeppelin.