public Builder<T>
			E(final Consumer<? super Expression.Builder<T>> builder) {
				final var eb = new Expression.Builder<T>();
				builder.accept(eb);
				expressions.add(eb.build());

				return this;
			}
Builder method for creating a rule expression.

@param builder the expression builder
@return {@code this} builder for method chaining
jenetics.ext/src/main/java/io/jenetics/ext/grammar/Cfg.java