public JavaStyleDocumentationWriterBuilder mappingFunction(Function<String, String> mappingFunction) {
        this.mappingFunction = mappingFunction;
        return this;
    }
Sets a custom mapping function to use when filtering documentation.

<p>Setting a custom mapping function will disable the default mapping
function that is used to escape the closing tokens of a block comment.
However, other mapping functions will still compose with a custom
mapping function if provided (e.g., escaping {@literal @} symbols via
{@link #escapeAtSignWithEntity(boolean)} still compose with a custom mapping function).

@param mappingFunction Mapping function to use. Set to {@code null} to use the default.
@return Returns the builder.
smithy-codegen-core/src/main/java/software/amazon/smithy/codegen/core/writer/JavaStyleDocumentationWriterBuilder.java