public static <T> List<T> build(List<? extends Buildable<T>> buildableList) {
            List<T> builtList = new ArrayList<T>(buildableList.size());
            for (Buildable<T> buildable : buildableList) {
                builtList.add(buildable.build());
            }
            return Collections.unmodifiableList(builtList);
        }
Converts the List of {@link Buildable}s into a List of the built object.

@param buildableList List of {@link Buildable}s to build.
@param <T>           Type of object being built
@return Unmodifiable list of built objects.
aws-java-sdk-stepfunctions/src/main/java/com/amazonaws/services/stepfunctions/builder/internal/Buildable.java