public void setHistory(List<Content> history) {
    this.history = new ArrayList<>(history);
  }
Sets the history to a list of Content.

@param history A list of {@link Content} containing interleaving conversation between "user"
    and "model".
java-vertexai/google-cloud-vertexai/src/main/java/com/google/cloud/vertexai/generativeai/ChatSession.java