public Builder metadataFilter(Predicate<String> metadataFilter) {
            this.metadataFilter = Objects.requireNonNull(metadataFilter);
            return this;
        }
Predicate that determines if a metadata is serialized.
@param metadataFilter Predicate that accepts a metadata key.
@return Returns the builder.
smithy-model/src/main/java/software/amazon/smithy/model/shapes/ModelSerializer.java