public int getRequiredCount() {
    return required_.size();
  }
<pre>
Optional. Required properties of Type.OBJECT.
</pre>

<code>repeated string required = 5 [(.google.api.field_behavior) = OPTIONAL];</code>

@return The count of required.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/Schema.java