public List<SymbolDependency> getDependencies() {
        List<SymbolDependency> resolved = new ArrayList<>();
        writers.values().forEach(s -> resolved.addAll(s.getDependencies()));
        return resolved;
    }
Gets all of the dependencies that have been registered in writers
created by the {@code CodegenWriterDelegator}.

<p>This method essentially just aggregates the results of calling
{@link CodegenWriter#getDependencies()} of each created writer into
a single array.

<p>This method may be overridden as needed (for example, to add in
some list of default dependencies or to inject other generative
dependencies).

@return Returns all the dependencies used in each {@code CodegenWriter}.
smithy-codegen-core/src/main/java/software/amazon/smithy/codegen/core/writer/CodegenWriterDelegator.java