code: public Problems validate( Changes changes ) {
          // Create a copy of this configuration ...
          Editor copy = edit();
          copy.apply(changes);
          RepositoryConfiguration updated = new RepositoryConfiguration(copy.unwrap(), this.getName());
          return updated.validate();
      }
docs: *
  Validate this configuration if the supplied changes were made to this. Note that this does <i>not</i> actually change this
  configuration.
  
  @param changes the proposed changes to this configuration's underlying document; never null
  @return the validation results; never null
  @see #edit()
  @see #validate()