Computing the quote should be done for a positive amount of tokens
When a policy is bought, a quote is requested from the `PolicyQuote` contract.\\n```\\nfunction \\_buyPolicyFor(\\n  address \\_policyHolderAddr,\\n  uint256 \\_epochsNumber,\\n  uint256 \\_coverTokens\\n) internal {\\n```\\n\\n```\\nuint256 \\_totalPrice = policyQuote.getQuote(\\_totalSeconds, \\_coverTokens, address(this));\\n```\\n\\nThe `getQuote` call is then forwarded to an internal function\\n```\\nfunction getQuote(uint256 \\_durationSeconds, uint256 \\_tokens, address \\_policyBookAddr)\\n  external view override returns (uint256 \\_daiTokens)\\n{\\n  \\_daiTokens = \\_getQuote(\\_durationSeconds, \\_tokens, \\_policyBookAddr);\\n}\\n```\\n\\n```\\nfunction \\_getQuote(uint256 \\_durationSeconds, uint256 \\_tokens, address \\_policyBookAddr)\\n  internal view returns (uint256)\\n{\\n```\\n\\nThere are some basic checks that make sure the total covered tokens with the requested quote do not exceed the total liquidity. On top of that check, it makes sure the total liquidity is positive.\\n```\\nrequire(\\_totalCoverTokens.add(\\_tokens) <= \\_totalLiquidity, "PolicyBook: Requiring more than there exists");\\nrequire(\\_totalLiquidity > 0, "PolicyBook: The pool is empty");\\n```\\n\\nBut there is no check for the number of quoted tokens. It should also be positive.
Add an additional check for the number of quoted tokens to be positive. The check could fail or return 0, depending on your use case.\\nIf you add a check for the number of quoted tokens to be positive, the check for `_totalLiquidity` to be positive becomes obsolete and can be removed.
```\\nfunction \\_buyPolicyFor(\\n  address \\_policyHolderAddr,\\n  uint256 \\_epochsNumber,\\n  uint256 \\_coverTokens\\n) internal {\\n```\\n