code: public ServiceCall<Void> deleteGrammar(DeleteGrammarOptions deleteGrammarOptions) {
      Validator.notNull(deleteGrammarOptions, "deleteGrammarOptions cannot be null");
      String[] pathSegments = { "v1/customizations", "grammars" };
      String[] pathParameters = { deleteGrammarOptions.customizationId(), deleteGrammarOptions.grammarName() };
      RequestBuilder builder = RequestBuilder.delete(RequestBuilder.constructHttpUrl(getEndPoint(), pathSegments,
          pathParameters));
      Map<String, String> sdkHeaders = SdkCommon.getSdkHeaders("speech_to_text", "v1", "deleteGrammar");
      for (Entry<String, String> header : sdkHeaders.entrySet()) {
        builder.header(header.getKey(), header.getValue());
      }
      builder.header("Accept", "application/json");
      return createServiceCall(builder.build(), ResponseConverterUtils.getVoid());
    }
docs: Delete a grammar.
  
  Deletes an existing grammar from a custom language model. The service removes any out-of-vocabulary (OOV) words
  associated with the grammar from the custom model's words resource unless they were also added by another resource
  or they were modified in some way with the **Add custom words** or **Add a custom word** method. Removing a grammar
  does not affect the custom model until you train the model with the **Train a custom language model** method. You
  must use credentials for the instance of the service that owns a model to delete its grammar.
  
  **See also:** [Deleting a grammar from a custom language
  model](https://cloud.ibm.com/docs/services/speech-to-text/).
  
  @param deleteGrammarOptions the {@link DeleteGrammarOptions} containing the options for the call
  @return a {@link ServiceCall} with a response type of Void