code: func (t *Terraform) Merge(t2 *Terraform) {
  	if t2.RequiredVersion != "" {
  		t.RequiredVersion = t2.RequiredVersion
  	}
  
  	if t2.Backend != nil {
  		t.Backend = t2.Backend
  	}
  }
docs: // Merge t with t2.
  // Any conflicting fields are overwritten by t2.