```\n// whitelist proposal\nif (proposal.flags[4]) {\n    require(!tokenWhitelist[address(proposal.tributeToken)], "cannot already have whitelisted the token");\n    require(!proposedToWhitelist[address(proposal.tributeToken)], 'already proposed to whitelist');\n    proposedToWhitelist[address(proposal.tributeToken)] = true;\n```\n