public GenerateContentResponse generateContent(String text) throws IOException {
    return generateContent(ContentMaker.fromString(text));
  }
Generates content from generative model given a text.

@param text a text message to send to the generative model
@return a {@link com.google.cloud.vertexai.api.GenerateContentResponse} instance that contains
    response contents and other metadata
@throws IOException if an I/O error occurs while making the API call
java-vertexai/google-cloud-vertexai/src/main/java/com/google/cloud/vertexai/generativeai/GenerativeModel.java