docs: public FormValidation doCheckDisplayName(@QueryParameter String displayName,
              @QueryParameter String jobName) {
          displayName = displayName.trim();
  
          if(LOGGER.isLoggable(Level.FINE)) {
              LOGGER.log(Level.FINE, "Current job name is " + jobName);
          }
  
          if(!isNameUnique(displayName, jobName)) {
              return FormValidation.warning(Messages.Jenkins_CheckDisplayName_NameNotUniqueWarning(displayName));
          }
          else if(!isDisplayNameUnique(displayName, jobName)){
              return FormValidation.warning(Messages.Jenkins_CheckDisplayName_DisplayNameNotUniqueWarning(displayName));
          }
          else {
              return FormValidation.ok();
          }
      }