public boolean canFail() {
        return true; // Default is to assume the step is always needed.
    }
Some steps cannot fail.
For a require rule if the last step cannot fail then this can be removed from the require list
to improve performance at run time.
@return If this specific step can or cannot fail.
analyzer/src/main/java/nl/basjes/parse/useragent/analyze/treewalker/steps/Step.java