public Bops<T> add(
				final int precedence,
				final Predicate<? super T> operators
			) {
				Predicate<? super T> ops = _operations.get(precedence);
				if (ops != null) {
					final Predicate<? super T> prev = ops;
					ops = token -> prev.test(token) || operators.test(token);
				} else {
					ops = operators;
				}
				_operations.put(precedence, ops);

				return this;
			}
Add a new operator predicate with its precedence.

@param precedence the precedence of the operators
@param operators the operators predicate
@return {@code this} builder, for method chaining
jenetics.ext/src/main/java/io/jenetics/ext/internal/util/FormulaParser.java