@java.lang.Override
  public java.lang.String getWorkflowId() {
    java.lang.Object ref = workflowId_;
    if (ref instanceof java.lang.String) {
      return (java.lang.String) ref;
    } else {
      com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
      java.lang.String s = bs.toStringUtf8();
      workflowId_ = s;
      return s;
    }
  }
<pre>
Required. The ID of the workflow to be created. It has to fulfill the
following requirements:

* Must contain only letters, numbers, underscores and hyphens.
* Must start with a letter.
* Must be between 1-64 characters.
* Must end with a number or a letter.
* Must be unique within the customer project and location.
</pre>

<code>string workflow_id = 3 [(.google.api.field_behavior) = REQUIRED];</code>

@return The workflowId.
java-workflows/proto-google-cloud-workflows-v1/src/main/java/com/google/cloud/workflows/v1/CreateWorkflowRequest.java