public boolean isOutputShape() {
        return shape().hasTrait(OutputTrait.ID);
    }
Check if this is a shape used exclusively for output.

<p>This is equivalent to calling {@code shape().hasTrait(OutputTrait.ID)}.

<p>Use the {@link CodegenDirector#createDedicatedInputsAndOutputs()} method
to ensure that every operation has a unique output shape marked with the
output trait.

@return Returns true if the shape is marked with the {@code output} trait.
@see ModelTransformer#createDedicatedInputAndOutput
smithy-codegen-core/src/main/java/software/amazon/smithy/codegen/core/directed/GenerateStructureDirective.java