``isGuestAccount`` will return false for values that aren't accounts

[PlatinMTA]

Describe the bug

Maybe not actually a bug, but isGuestAccount shouldn't accept values that arent accounts, or if it does it should have a different return value.

isGuestAccount("something") will return false, same with any other value that is not an account
There is a warning being thrown out, but the return value should be something different than false, maybe nil

so isGuestAccount should return another value to differentiate
Maybe it should return true, since probably the only reason you are checking if an account is guest is to negate this value and cancel the method/function.

Steps to reproduce

1. start runcode
2. /run isGuestAccount("something")

Version

No response

Additional context

No response

Relevant log output

Security Policy

• I have read and understood the Security Policy and this issue is not security related.