public Builder afterFailure(final BiConsumer<Bindings, Throwable> afterFailure) {
                this.afterFailure = afterFailure;
                return this;
            }
Specifies the function to execute if the script evaluation fails.  This function can also be
specified globally on {@link GremlinExecutor.Builder#afterFailure(BiConsumer)}.
gremlin-groovy/src/main/java/org/apache/tinkerpop/gremlin/groovy/engine/GremlinExecutor.java