public function getHelpMessage()
    {
        $message = $this->message . "\n";

        if (is_array($this->readEnv)) {
            foreach ($this->readEnv as $envVarName => $value) {
                $message .= $this->format($envVarName, $value);
            }
        }

        $message .= <<< 'EOL'

Set environment variables properly like the following.
For Travis users:

  - TRAVIS
  - TRAVIS_JOB_ID

For CircleCI users:

  - CIRCLECI
  - CIRCLE_BUILD_NUM
  - COVERALLS_REPO_TOKEN

For Jenkins users:

  - JENKINS_URL
  - BUILD_NUMBER
  - COVERALLS_REPO_TOKEN

For AppVeyor users:

  - APPVEYOR
  - APPVEYOR_BUILD_NUMBER

From local environment:

  - COVERALLS_RUN_LOCALLY
  - COVERALLS_REPO_TOKEN

EOL;

        return $message;
    }