public final Map<String, W> getWriters() {
        return Collections.unmodifiableMap(writers);
    }
Returns an immutable {@code Map} of created {@code SymbolWriter}s.

<p>Each map key is the relative filename where the code will be written
in the {@link FileManifest}, and each map value is the associated
{@code SymbolWriter} of type {@code T}.

@return Returns the immutable map of files to writers.
smithy-codegen-core/src/main/java/software/amazon/smithy/codegen/core/WriterDelegator.java