An `Error` object tracks and reports errors that occur during request handling or middleware execution in a [`Router`]. Errors are collected in a list, and the `occurred` active binding indicates whether any errors have been set.
An [`R6::R6Class`] generator for `Error` objects.
[Middleware], [Router], [handleErrors]
errorsCharacter vector of recorded error messages.
occurredLogical; `TRUE` if any errors have been recorded.