private void warnRedundantUse(String whatWasUsed1, @Nullable String whatWasUsed2) {
            if (warnedRedundantUse) {
                return;
            }

            warnedRedundantUse = true;
            final StringBuilder buf = new StringBuilder();
            buf.append("Found a redundant ");
            if (whatWasUsed2 != null) {
                buf.append("combined ");
            }
            buf.append("use of ")
               .append(whatWasUsed1);
            if (whatWasUsed2 != null) {
                buf.append(" and ").append(whatWasUsed2);
            }
            buf.append(" in '")
               .append(typeElement)
               .append('\'');

            if (typeElement != annotatedElement) {
                buf.append(" of '")
                   .append(annotatedElement)
                   .append('\'');
            }

            if (annotationType != null) {
                buf.append(" (type: ")
                   .append(annotationType.getSimpleName())
                   .append(')');
            }

            logger.warn(buf.toString());
        }
Sets an {@link AggregationStrategy} for the element.
core/src/main/java/com/linecorp/armeria/internal/server/annotation/AnnotatedValueResolver.java