== Why is this an issue? There are two types of stream operations: intermediate operations, which return another stream, and terminal operations, which return something other than a stream. Intermediate operations are lazy, meaning they aren't actually executed until and unless a terminal stream operation is performed on their results. Consequently, if the result of an intermediate stream operation is not fed to a terminal operation, it serves no purpose, which is almost certainly an error. === Noncompliant code example [source,java] ---- widgets.stream().filter(b -> b.getColor() == RED); // Noncompliant ---- === Compliant solution [source,java] ---- int sum = widgets.stream() .filter(b -> b.getColor() == RED) .mapToInt(b -> b.getWeight()) .sum(); Stream pipeline = widgets.stream() .filter(b -> b.getColor() == GREEN) .mapToInt(b -> b.getWeight()); sum = pipeline.sum(); ---- == Resources * https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html#StreamOps[Stream Operations] ifdef::env-github,rspecator-view[] ''' == Implementation Specification (visible only on this page) === Message Refactor the code so this stream pipeline is used. === Highlighting The intermediate stream function call endif::env-github,rspecator-view[]